Obesity and Body Mass Index are Not Associated with Suboptimal Quality of Bowel Preparation for Colonoscopy

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This study aims to explore the association between obesity and the quality of bowel preparation. Methods We evaluated the efficacy of bowel preparation and colonoscopy outcomes according to obesity and BMI in subjects who underwent screening colonoscopy at a single hospital between January 1, 2021, and December 31, 2022. Overall, the quality of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS). Results The 4,699 subjects who underwent screening colonoscopy were classified as the non-obese (n = 3,058, 65.1%) and obese (n = 1, 641, 34.9%) groups. The quality of bowel preparation measured by the efficacy of preparation in each segment, overall high-quality cleaning and successful cleansing, and rate of colonoscopy termination due to inadequate preparation were not significantly different between the non-obese and obese groups and according to BMI subgroups. Polyp and adenoma detection rates were significantly higher in the obese group than in the non-obese group after propensity score matching for age and sex, which are well-known risk factors for colorectal neoplasia (60.1% vs 54.1%, p = 0.001 and 39.2% vs 34.6%, p = 0.006, respectively). Conclusions Obesity and BMI were not associated with suboptimal preparation for colonoscopy when low-volume agents were used. In addition, polyp and adenoma detection rates were significantly higher in the obese group than in the non-obese group. Adenoma Body mass index Cathartics Colonoscopy Obesity Introduction Colonoscopy is the gold standard for colorectal cancer (CRC) screening [ 1 ], but success of a colonoscopy depends on quality of bowel preparation as 20–44% of colonoscopy participants have an inadequate preparation [ 2 ]. Obesity of higher body mass index (BMI) was reported as a risk factor that is associated with inadequate bowel preparation in previous studies [ 3 – 5 ]. However, they were limited by retrospective design and variable indications of colonoscopy, and mostly used 4 L polyethylene glycol (PEG) for preparation without reporting of patient compliance [ 3 – 5 ]. Furthermore, conflicting results are also consistently reported showing that obesity or BMI was not related to inadequate bowel preparation [ 2 , 6 – 8 ]. For example, prospective US study from 1314 subjects, out of which 73% were overweight or obese, showed that BMI was not predictive of inadequate bowel preparation for colonoscopy [ 6 ]. Inconsistent results in previous studies may be explained by the differences in study design, study population, definition of obesity, bowel preparation agent (4 L PEG vs low-volume agent), bowel preparation scale and definitions of inadequate preparation between these studies. Therefore, the association between obesity, BMI, and bowel preparation quality remains unclear. Obesity has become an epidemic in most countries, including Korea, and is associated with an increased risk of colorectal neoplasia. Therefore, the demand for colonoscopy in these individuals will be steadily increasing. The effect of obesity on the quality of bowel preparation, and consequently, the adequacy of colonoscopy, should be further evaluated. Furthermore, additional studies on the association between obesity and the quality of preparation are warranted in Asian countries because eating habits and the definition of obesity are not the same between the East and West, and most previous studies on this issue have been conducted in western countries [ 2 – 8 ]. In this study, we evaluated bowel preparation quality and colonoscopy outcomes according to obesity and BMI in patients who underwent screening colonoscopy. Methods Study Design This was a retrospective study for the quality of bowel preparation and colonoscopy outcomes according to obesity and BMI subgroups in healthy subjects who underwent screening colonoscopy at a single ‘Health Promotion Center’ in Korea between January 1, 2021, and December 31, 2022. In this study, the following data were collected from each patient: demographic, medication history, previous abdominal surgery, comorbid disease, laboratory data on the day of endoscopy, colonoscopy data, quality of bowel cleansing [ 9 ]. Based on the clinical practice guidelines for obesity in Asian countries, BMI groups were defined as BMI < 18.5 Kg/m 2 (underweight), 18.5–22.9 Kg/m 2 (normal), 23.0-24.9 Kg/m 2 (overweight) and ≥ 25 Kg/m 2 (obesity) [ 10 ]. In addition, laboratory data were also collected on the day of colonoscopy for the monitoring of potential adverse events associated with bowel preparation: blood urea nitrogen (BUN), sodium, chloride, potassium, calcium, and phosphorus levels. Abnormal laboratory data were defined as values beyond the normal range for each variable. As laboratory data were not measured for all participants, only those with complete data were analyzed. Subjects Healthy subjects who were 18 years of age or older, underwent screening colonoscopy and possessed sufficient medical information were included. At our center, screening colonoscopy is not recommended for patients with the following conditions: American Society of Anesthesiologists physical status index > III, acute myocardial infarction within 24 weeks, history of significant constipation (< 3 bowel movements per week with regular laxatives), known or suspected ileus, gastrointestinal obstruction, bowel perforation, toxic colitis or megacolon, active intestinal bleeding, severe renal insufficiency, physical or mental disability that would interfere with colonoscopy, pregnant or lactating women, or coronavirus disease-19 diagnosis within 1 month. The requirement for informed consent was waived owing to the retrospective nature of the study. This study was approved by the Institutional Ethics Committee (KHNMC IRB 2023-03-008) and conducted in accordance with the principles of the Declaration of Helsinki and Good Clinical Practice guidelines. Colonoscopy Colonoscopies were performed by two highly experienced, board-certified gastroenterologists who had performed 10,000 colonoscopies using a high-definition colonoscopy system (290 series; Olympus America, Center Valley, PA, USA). At our center, all subjects were instructed to consume a low-residue diet for three days prior to their colonoscopy and were restricted to a soft or liquid diet for dinner on the day before colonoscopy. Bowel preparation was performed with low volume agents, such as oral sulfate tablet (OST) (Orafang®; Phambio Korea, Chungju, Korea) or 1 L PEG with ascorbic acid (PEG/Asc) (CleanViewAL®; Taejoon Pharm Co., Ltd., Seoul, Korea) according to the preference of subjects. All endoscopies were performed during the morning hours. The subjects were instructed to consume the preparation agents as a split-dose regimen at home: the first dose was administered at 19:00–21:00 on the night before colonoscopy, and the second dose at 05:00–08:00, within 2–3 h ahead of the scheduled time of colonoscopy. Patients taking aspirin, antiplatelet agents, or anticoagulants were instructed to discontinue their medications according to the guidelines. Efficacy of Preparation and Colonoscopy Outcomes Primary outcome was the quality of the bowel preparation, which was assessed using the Boston Bowel Preparation Scale (BBPS) [ 11 – 13 ]. In this study, bowel preparation was considered adequate if the overall BBPS score was 6 or higher [ 13 ]. High-quality bowel preparation on overall evaluation was defined as a BBPS score of 3 for all segments, and successful overall bowel preparation was defined as a BBPS score ≥ 2 for all segments [ 13 , 14 ]. Secondary outcomes were polyp detection rate (PDR) and adenoma detection rate (ADR), which were calculated as the percentage of patients with at least one polyp (for PDR) or adenoma (for ADR) seen on colonoscopy. Statistical Analysis Continuous variables are presented as the mean ± standard deviation (SD), whereas categorical variables are expressed as number (percentages). For comparisons between the two groups, normally distributed variables were analyzed using an independent t ‑test, whereas the Wilcoxon signed-rank test was applied to non-normally distributed data. When comparing the four groups stratified by BMI, analysis of variance was used for normally distributed data, and the Kruskal-Wallis test was employed for non-normally distributed variables. Additionally, propensity score matching (PSM) was performed to adjust for sex and age, and the propensity scores were estimated using a logistic regression model. PSM was performed using the nearest-neighbor method with a caliper of 0.10. All statistical tests were two-sided, and a p‑value < 0.05 was considered statistically significant. Statistical analyses were conducted using R software (version 4.2.3). Results Baseline Characteristics of Subjects Among the 4,718 patients who underwent screening colonoscopy, 4,699 were eligible for the study after excluding 19 patients with insufficient data. Table 1 shows the baseline characteristics of the 4,699 participants in the non-obese (n = 3058, 65.1%) and obese (n = 1 641, 34.9%) groups. Age, age group, comorbid diseases, current medication use (except antiplatelet agents), history of abdominal surgery, indications for colonoscopy, and type of preparation agent were not different between the two groups. The obese group was characterized by male predominance and more antiplatelet agent users ( p < 0.001). Table 1 Baseline characteristics of the subjects Baseline characteristics Non-obesity (BMI < 25kg/m 2 ) (n = 3,058) Obesity (BMI ≥ 25kg/m 2 ) (n = 1,641) P value Age (years), mean ± SD 52.7 ± 11.2 52.5 ± 11.1 0.562 Age group, n (%) 0.836 < 50 years 1,139 (37.2) 617 (37.6) ≥ 50 years 1,919 (62.8) 1,024 (62.4) Sex, n (%) < 0.001 Male 1,573 (51.4) 1,216 (74.1) Female 1485 (48.6) 425 (25.9) Comorbid diseases, n (%) Hypertension 141 (4.6) 91 (5.5) 0.181 Diabetes mellitus 140 (4.6) 87 (5.3) 0.302 Ischemic heart disease 173 (5.7) 96 (5.9) 0.837 Cerebrovascular disease 26 (0.9) 19 (1.2) 0.382 Current medication use, n (%) Antiplatelet agents (including aspirin) 209 (6.8) 187 (11.4) < 0.001 Anticoagulants 12 (0.4) 10 (0.6) 0.415 Non-steroidal anti-inflammatory drugs 58 (1.9) 41 (2.5) 0.207 History of abdominal surgery, n (%) 630 (20.6) 318 (19.4) 0.343 Indication of colonoscopy, n (%) Screening/surveillance 3,058 (100.0) 1,641 (100.0) - Type of preparation agents, n (%) 0.185 1L PEG/Asc 1,360 (44.5) 696 (42.4) Oral sulfate tablet 1,698 (55.5) 945 (57.6) BMI, body mass index; SD, standard deviation; PEG/Asc, polyethylene glycol/ascorbic acid. Quality of Preparation and Colonoscopy Outcomes Table 2 shows the bowel preparation quality and colonoscopy outcomes before and after PSM. The quality of bowel preparation measured by the efficacy of preparation in each segment with BBPS, overall high-quality cleaning, overall successful cleansing, and rate of colonoscopy termination due to inadequate preparation were not significantly different between the non-obese and obese groups before and after PSM. Table 2 Bowel preparation quality and colonoscopy outcomes before and after propensity score matching a Before PSM After PSM a Non-obesity (n = 3,058) Obesity (n = 1,641) P value Non-obesity (n = 1,641) Obesity (n = 1,641) P value Quality of bowel preparation Efficacy of preparation (BBPS), mean ± SD Total score (0–9) 7.8 ± 1.5 7.8 ± 1.5 0.325 7.8 ± 1.5 7.8 ± 1.5 0.717 Right-sided colon (0–3) 2.5 ± 0.6 2.5 ± 0.6 0.427 2.5 ± 0.6 2.5 ± 0.6 0.937 Transverse colon (0–3) 2.8 ± 0.5 2.8 ± 0.5 0.582 2.8 ± 0.5 2.8 ± 0.5 0.419 Left-sided colon (0–3) 2.6 ± 0.6 2.6 ± 0.6 0.404 2.5 ± 0.6 2.6 ± 0.6 0.913 High-quality cleansing, n (%) 1,618 (52.9%) 8,39 (51.1) 0.256 852 (51.9) 839 (51.1) 0.675 Successful cleansing, n (%) 2,823 (92.3%) 1,516 (92.4) 0.980 1,519 (92.6) 1,516 (92.4) 0.895 Termination due to inadequate prep, n (%) 4 (0.1) 1 (0.1) 0.817 7.8 ± 1.5 7.8 ± 1.5 0.717 Colonoscopy outcome, n (%) Cecal intubation rate 5 (0.2) 1 (0.1) 0.610 1 (0.1) 1 (0.1) 1.000 Polyp detection rate 1,574 (51.5) 986 (60.1) < 0.001 887 (54.1) 986 (60.1) 0.001 Adenoma detection rate 1,004 (32.8) 644 (39.2) < 0.001 567 (34.6) 644 (39.2) 0.006 Colorectal cancer detection rate 3 (0.1) 1 (0.1) 1.000 1 (0.1) 1 (0.1) 1.000 PSM, propensity score matching; BBPS, Boston Bowel Preparation Scale; SD, standard deviation a Propensity score matched for age and sex. The overall successful cleaning rate was 92.3%, the overall cecal intubation rate was 99.9%, and the overall ADR of 35.1% in this study indicates high-quality colonoscopy. Cecal intubation and detection rates of CRC were not significantly different between the non-obese and obese groups before and after PSM. PDR and ADR were higher in the obese group than in the non-obese group before PSM (both p < 0.001). After PSM, the PDR and ADR were also significantly higher in the obese group than in the non-obese group (60.1% vs . 54.1%, p = 0.001, and 39.2% vs . 34.6%, p = 0.006, respectively). Quality of Preparation and Colonoscopy Outcomes According to BMI Table 3 shows quality of bowel preparation and colonoscopy outcomes according to BMI subgroups after PSM. The quality of bowel preparation measured by efficacy of preparation in each segment with BBPS, overall high-quality cleaning, overall successful cleansing, and rate of colonoscopy termination due to inadequate preparation, were not significantly different according to BMI subgroups. PDR and ADR were increased significantly in proportion as BMI increased (both p < 0.001). In addition, cecal intubation rate and detection rate of CRC was not significantly different according to BMI subgroups. Table 3 Quality of preparation and colonoscopy outcomes according to body mass index (after propensity score matching a ) Body mass index group b P value Underweight (n = 62) Normal (n = 842) Overweight (n = 737) Obesity (n = 1,641) Quality of bowel preparation Efficacy of preparation (BBPS), mean ± SD Total score (0–9) 7.5 ± 1.5 7.8 ± 1.5 7.7 ± 1.5 7.8 ± 1.5 0.854 Right-sided colon (0–3) 2.4 ± 0.6 2.5 ± 0.6 2.5 ± 0.6 2.5 ± 0.6 0.992 Transverse colon (0–3) 2.7 ± 0.5 2.7 ± 0.5 2.7 ± 0.5 2.8 ± 0.5 0.738 Left-sided colon (0–3) 2.5 ± 0.6 2.5 ± 0.6 2.5 ± 0.6 2.6 ± 0.6 0.346 High quality cleansing (all segment ≥ 3), n (%) 32 (51.6) 443 (52.6) 377 (51.2) 839 (51.1) 0.909 Successful cleansing (all segment ≥ 2), n (%) 58 (93.5) 779 (92.5) 682 (92.5) 1,516 (92.4) 0.988 Termination due to inadequate prep, n (%) 0 (0.0) 1 (0.1) 0 (0.0) 1 (0.1) 0.813 Colonoscopy outcome, n (%) Cecal intubation rate 0 (0.0) 1 (0.1) 0 (0.0) 1 (0.1) 0.813 Polyp detection rate 30 (48.4) 424 (50.4) 433 (58.9) 986 (60.1) < 0.001 Adenoma detection rate 15 (24.2) 269 (31.9) 283 (38.4) 644 (39.2) < 0.001 Colorectal cancer detection rate 0 (0.0) 1 (0.1) 0 (0.0) 1 (0.1) 0.813 PSM, propensity score matching; BBPS, Boston Bowel Preparation Scale; SD, standard deviation a Propensity score matched for age and sex. b Body mass index group was defined as underweight (< 18.5 kg/m 2 ), normal (18.5–22.9 kg/m 2 ), overweight (23.0-24.9 kg/m 2 ), and obesity (≥ 25 kg/m 2 ). Laboratory Data Table 4 shows laboratory data on the day of colonoscopy. The proportion of participants with abnormal potassium and calcium levels was significantly higher in the non-obese group than in the obese group. However, the actual numerical differences were negligible and subclinical in all the cases. Table 4 Laboratory data on day of colonoscopy according to obesity (after propensity score matching a ) Laboratory data Non-obesity (n = 1,641) Obesity (n = 1,641) P value BUN (mg/dL), mean ± SD 13.7 ± 3.8 13.8 ± 4.1 0.881 Beyond NR (6–20), n (%) 78 (4.8) 77 (4.7) 1.000 Sodium (mEq/L), mean ± SD 140.9 ± 2.5 140.8 ± 4.7 0.699 Beyond NR (136–145), n (%) 50 (4.4) 51 (4.4) 1.000 Potassium (mEq/L), mean ± SD 4.5 ± 0.4 4.4 ± 0.4 < 0.001 Beyond NR (3.5–5.1), n (%) 61 (5.4) 38 (3.3) 0.014 Chloride (mEq/L), mean ± SD 102.7 ± 3.7 102.8 ± 4.7 0.098 Beyond NR (98–107), n (%) 139 (14.9) 111 (11.4) 0.026 Calcium (mg/dL), mean ± SD 9.9 ± 0.5 9.9 ± 0.4 < 0.001 Beyond NR (9.1–10.6), n (%) 133 (8.1) 89 (5.4) 0.003 Phosphorus (mg/dL), mean ± SD 3.7 ± 0.7 3.7 ± 0.7 0.013 Beyond NR (2.5–4.5), n (%) 197 (12.0) 174 (10.6) 0.223 BUN, blood urea nitrogen; SD, standard deviation; NR, normal range. a Propensity score matched for age and sex. Discussion To the best of our knowledge, this is the largest study on the quality of bowel preparation in non-obese and obese subjects from Asian populations. In this study, the quality of bowel preparation measured by the efficacy of preparation in each segment with BBPS, overall high-quality cleaning, overall successful cleansing, and rate of colonoscopy termination due to inadequate preparation were not significantly different between the non-obese and obese groups as well as the BMI subgroups. Our study supports the finding that obesity and BMI are not related to inadequate bowel preparation, which is consistent with previous Western studies [ 2 , 6 – 8 ]. Previous reports supporting the positive association between obesity and inadequate bowel preparation leaved much room for debate due to many limitations [ 3 – 5 , 15 ]. American guideline [ 15 ] published on bowel preparation stated that obesity might be a possible predictor of inadequate bowel preparation based on two previous studies [ 3 , 4 ]. Borg et al. showed that BMI ≥ 25 kg/m 2 is an independent risk factor of inadequate bowel preparation in a retrospective study of 1588 subjects [ 3 ]. However, this study was limited, as it included only 58.4% of screening/surveillance colonoscopies with variable indications, such as gastrointestinal bleeding (21.5%) and constipation (12.1%). In addition, 87.0% of the participants used PEG without reporting patient compliance. Fayad et al . also showed that BMI ≥ 30 kg/m 2 was an independent risk factor for inadequate preparation in retrospective study of 2163 subjects [ 4 ]. This study also included only 68.7% of screening/surveillance indications. In addition, 91.1% of the subjects used 4 L PEG without reporting patient compliance. A retrospective cohort study with 1082 subject also reported that obesity was significantly associated with inadequate bowel preparation [ 5 ]. However, this study was also limited as 13.3% of diagnostic colonoscopy was included and variable bowel preparation agents were used, such as 4 L PEG, picoprep and other agents. Compared with these studies [ 3 – 5 ], our current study was characterized by 100% screening colonoscopy and 100% use of low-volume agents. More recently, European guidelines published in 2019 did not state an association between obesity and bowel preparation [ 16 ]. There is no evidence in the current literature supporting a physiological explanation for the potential association between obesity and bowel preparation quality. It is possible that patient compliance is responsible for the inconsistent results of previous studies. Noncompliance with preparation instructions may be higher among obese subjects and therefore may be a reason for the positive association between obesity and the quality of bowel preparation. This may explain the negative association between obesity and bowel preparation quality when low-volume agents were used in previous studies [ 8 , 17 ] and in the current study. However, no association was reported between obesity and bowel preparation using 4 L PEG in three prospective studies [ 6 , 18 , 19 ] and a retrospective study [ 20 ]. Many previous studies evaluated the association between obesity/BMI and the quality of bowel preparation using the Aronchick scale [ 3 , 4 , 6 , 7 , 18 – 20 ], which is subjective and variable in adequacy of preparation assessment. Only one prospective study [ 17 ] that used a validated BBPS, similar to our study, showed no association between the quality of preparation and obesity. Therefore, growing evidence, including that of the current study, supports no association between obesity/BMI and the quality of bowel preparation. We also found that PDR and ADR were significantly higher in the obese group than in the non-obese group after PSM for age and sex, which are well-known risk factors for colorectal neoplasia ( p = 0.001 and p = 0.006, respectively). In addition, PDR and ADR increased significantly in proportion as BMI increased (both p < 0.001). These findings are consistent with many previous studies that obesity is associated with increased detection of colorectal precursor lesions [ 21 , 22 ]. In a large population-based study from Poland, obesity was associated with higher ADR than normal weight group (22.03% vs 17.11%, p < 0.001) [ 21 ]. In a systemic review and meta-analysis, obesity (BMI ≥ 30 kg/m 2 ) was a significant risk factor for colorectal adenoma with a pooled odd ratio of 1.47 (95% confidence interval = 1.18–1.83) [ 22 ]. Our study is the largest Asian study focusing on the quality of bowel preparations associated with obesity and BMI during screening colonoscopy. Despite the retrospective design, the colonoscopy quality in this study was excellent, with was represented by 92.3% overall successful cleaning rate of 99.9% overall cecal intubation rate of 35.1% overall ADR. In addition, detailed clinical information, including comorbidities and medication history, was obtained from the health check-up data. Despite these strengths, this study had several limitations. First, we could not assess patient compliance, even though low-volume agents were used, because of the retrospective nature of the study. However, the tolerability of 1 L PEG/Asc and OST was excellent in clinical trials. Second, our findings may not be generalizable to other populations as our subjects were relatively healthy individuals who underwent medical checkups. Therefore, baseline characteristics of the study population may differ from those of the general population. Third, given the differences in obesity definition between Asian and Western populations [ 10 ], obesity was defined as a BMI ≥ 25 Kg/m 2 in this study. This distinction in obesity thresholds has been widely acknowledged in many studies related to obesity. Finally, only 1 L of PEG/Asc and OST were used in this study; therefore, other low-volume agents should be evaluated in future studies. In conclusion, this study showed that obesity and BMI were not associated with suboptimal bowel preparation for colonoscopy using low-volume agents. In addition, PDR and ADR were significantly higher in the obese group than in the non-obese group. Prospective studies using low-volume agents are warranted to confirm these findings. Declarations Supplementary Information The online version contains supplementary material available at https:// doi. org/ Acknowledgments The authors thank Hyo Been Lee for statistical analysis. Author Contributions JMC contributed toward conceptualization, interpretation, draft of manuscript, and review of manuscript; HIC contributed toward acquisition of the data, analysis of the data, interpretation, and review of manuscript; and ML contributed toward conceptualization, acquisition of the data, analysis of the data, interpretation, draft of manuscript, and review of manuscript. Funding None. Data Availability No datasets were generated or analyzed during the current study. Declarations Conflict of interest The authors have nothing to disclose and have no potential conflicts. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, which permits any non-commercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. References Rex DK, Boland CR, Dominitz JA, et al. Colorectal cancer screening: Recommendations for physicians and patients from the US multi-society task force on colorectal cancer. 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Scand J Gastroenterol. 2013;48:136–146. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 01 Jul, 2025 Read the published version in Digestive Diseases and Sciences → Version 1 posted Editorial decision: Revision requested 18 May, 2025 Reviews received at journal 16 May, 2025 Reviews received at journal 09 May, 2025 Reviewers agreed at journal 03 May, 2025 Reviewers agreed at journal 02 May, 2025 Reviews received at journal 02 May, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers invited by journal 30 Apr, 2025 Editor assigned by journal 28 Apr, 2025 Submission checks completed at journal 24 Apr, 2025 First submitted to journal 24 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6521515","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":451395343,"identity":"0ffa90c5-805e-41b5-91d6-d288894c74ce","order_by":0,"name":"Hyung Il Choi","email":"","orcid":"","institution":"Kyung Hee University Hospital at Gangdong","correspondingAuthor":false,"prefix":"","firstName":"Hyung","middleName":"Il","lastName":"Choi","suffix":""},{"id":451395344,"identity":"58601795-6d54-451e-b677-b4f319650317","order_by":1,"name":"Moonhyung Lee","email":"","orcid":"","institution":"Kyung Hee University Hospital at Gangdong","correspondingAuthor":false,"prefix":"","firstName":"Moonhyung","middleName":"","lastName":"Lee","suffix":""},{"id":451395345,"identity":"94161ef1-9ff5-411e-9756-a7d4b8437205","order_by":2,"name":"Jae Myung Cha","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAArUlEQVRIiWNgGAWjYDCCAwxsDAwVCQkwHrFazpCshbGNFC18tw8/e/BzXlqewQHmhx8YztwjrEXyXJq5Ye+2nGKDA2zGEgw3iglrMTjDwybBu60iccMBBjMGhg8JxGmR/DsHpIX9G/FapHkbcoBaeIC23CBCi+QZNjNpmWNpiTMP8xRLJJwhQgvfGeZnkm9qkhP7jrdv/PDhGBFaEIAZiEnSMApGwSgYBaMANwAA8Zs8KVe9EcUAAAAASUVORK5CYII=","orcid":"","institution":"Kyung Hee University Hospital at Gangdong","correspondingAuthor":true,"prefix":"","firstName":"Jae","middleName":"Myung","lastName":"Cha","suffix":""}],"badges":[],"createdAt":"2025-04-24 14:08:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6521515/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6521515/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10620-025-09195-5","type":"published","date":"2025-07-01T15:58:09+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":86179816,"identity":"47732128-3edd-4c3b-84fe-87389be93e04","added_by":"auto","created_at":"2025-07-07 16:19:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":855638,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6521515/v1/e1eef8d5-22c7-4b21-9b27-c46c9db7467f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eObesity and Body Mass Index are Not Associated with Suboptimal Quality of Bowel Preparation for Colonoscopy \u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eColonoscopy is the gold standard for colorectal cancer (CRC) screening [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], but success of a colonoscopy depends on quality of bowel preparation as 20\u0026ndash;44% of colonoscopy participants have an inadequate preparation [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Obesity of higher body mass index (BMI) was reported as a risk factor that is associated with inadequate bowel preparation in previous studies [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, they were limited by retrospective design and variable indications of colonoscopy, and mostly used 4 L polyethylene glycol (PEG) for preparation without reporting of patient compliance [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Furthermore, conflicting results are also consistently reported showing that obesity or BMI was not related to inadequate bowel preparation [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. For example, prospective US study from 1314 subjects, out of which 73% were overweight or obese, showed that BMI was not predictive of inadequate bowel preparation for colonoscopy [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Inconsistent results in previous studies may be explained by the differences in study design, study population, definition of obesity, bowel preparation agent (4 L PEG \u003cem\u003evs\u003c/em\u003e low-volume agent), bowel preparation scale and definitions of inadequate preparation between these studies. Therefore, the association between obesity, BMI, and bowel preparation quality remains unclear.\u003c/p\u003e \u003cp\u003eObesity has become an epidemic in most countries, including Korea, and is associated with an increased risk of colorectal neoplasia. Therefore, the demand for colonoscopy in these individuals will be steadily increasing. The effect of obesity on the quality of bowel preparation, and consequently, the adequacy of colonoscopy, should be further evaluated. Furthermore, additional studies on the association between obesity and the quality of preparation are warranted in Asian countries because eating habits and the definition of obesity are not the same between the East and West, and most previous studies on this issue have been conducted in western countries [\u003cspan additionalcitationids=\"CR3 CR4 CR5 CR6 CR7\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this study, we evaluated bowel preparation quality and colonoscopy outcomes according to obesity and BMI in patients who underwent screening colonoscopy.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design\u003c/h2\u003e \u003cp\u003e This was a retrospective study for the quality of bowel preparation and colonoscopy outcomes according to obesity and BMI subgroups in healthy subjects who underwent screening colonoscopy at a single \u0026lsquo;Health Promotion Center\u0026rsquo; in Korea between January 1, 2021, and December 31, 2022. In this study, the following data were collected from each patient: demographic, medication history, previous abdominal surgery, comorbid disease, laboratory data on the day of endoscopy, colonoscopy data, quality of bowel cleansing [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Based on the clinical practice guidelines for obesity in Asian countries, BMI groups were defined as BMI\u0026thinsp;\u0026lt;\u0026thinsp;18.5 Kg/m\u003csup\u003e2\u003c/sup\u003e (underweight), 18.5\u0026ndash;22.9 Kg/m\u003csup\u003e2\u003c/sup\u003e (normal), 23.0-24.9 Kg/m\u003csup\u003e2\u003c/sup\u003e (overweight) and \u0026ge;\u0026thinsp;25 Kg/m\u003csup\u003e2\u003c/sup\u003e (obesity) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In addition, laboratory data were also collected on the day of colonoscopy for the monitoring of potential adverse events associated with bowel preparation: blood urea nitrogen (BUN), sodium, chloride, potassium, calcium, and phosphorus levels. Abnormal laboratory data were defined as values beyond the normal range for each variable. As laboratory data were not measured for all participants, only those with complete data were analyzed.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSubjects\u003c/h3\u003e\n\u003cp\u003eHealthy subjects who were 18 years of age or older, underwent screening colonoscopy and possessed sufficient medical information were included. At our center, screening colonoscopy is not recommended for patients with the following conditions: American Society of Anesthesiologists physical status index\u0026thinsp;\u0026gt;\u0026thinsp;III, acute myocardial infarction within 24 weeks, history of significant constipation (\u0026lt;\u0026thinsp;3 bowel movements per week with regular laxatives), known or suspected ileus, gastrointestinal obstruction, bowel perforation, toxic colitis or megacolon, active intestinal bleeding, severe renal insufficiency, physical or mental disability that would interfere with colonoscopy, pregnant or lactating women, or coronavirus disease-19 diagnosis within 1 month. The requirement for informed consent was waived owing to the retrospective nature of the study. This study was approved by the Institutional Ethics Committee (KHNMC IRB 2023-03-008) and conducted in accordance with the principles of the Declaration of Helsinki and Good Clinical Practice guidelines.\u003c/p\u003e\n\u003ch3\u003eColonoscopy\u003c/h3\u003e\n\u003cp\u003eColonoscopies were performed by two highly experienced, board-certified gastroenterologists who had performed 10,000 colonoscopies using a high-definition colonoscopy system (290 series; Olympus America, Center Valley, PA, USA). At our center, all subjects were instructed to consume a low-residue diet for three days prior to their colonoscopy and were restricted to a soft or liquid diet for dinner on the day before colonoscopy. Bowel preparation was performed with low volume agents, such as oral sulfate tablet (OST) (Orafang\u0026reg;; Phambio Korea, Chungju, Korea) or 1 L PEG with ascorbic acid (PEG/Asc) (CleanViewAL\u0026reg;; Taejoon Pharm Co., Ltd., Seoul, Korea) according to the preference of subjects. All endoscopies were performed during the morning hours. The subjects were instructed to consume the preparation agents as a split-dose regimen at home: the first dose was administered at 19:00\u0026ndash;21:00 on the night before colonoscopy, and the second dose at 05:00\u0026ndash;08:00, within 2\u0026ndash;3 h ahead of the scheduled time of colonoscopy. Patients taking aspirin, antiplatelet agents, or anticoagulants were instructed to discontinue their medications according to the guidelines.\u003c/p\u003e\n\u003ch3\u003eEfficacy of Preparation and Colonoscopy Outcomes\u003c/h3\u003e\n\u003cp\u003ePrimary outcome was the quality of the bowel preparation, which was assessed using the Boston Bowel Preparation Scale (BBPS) [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In this study, bowel preparation was considered adequate if the overall BBPS score was 6 or higher [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. High-quality bowel preparation on overall evaluation was defined as a BBPS score of 3 for all segments, and successful overall bowel preparation was defined as a BBPS score\u0026thinsp;\u0026ge;\u0026thinsp;2 for all segments [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Secondary outcomes were polyp detection rate (PDR) and adenoma detection rate (ADR), which were calculated as the percentage of patients with at least one polyp (for PDR) or adenoma (for ADR) seen on colonoscopy.\u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eContinuous variables are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), whereas categorical variables are expressed as number (percentages). For comparisons between the two groups, normally distributed variables were analyzed using an independent \u003cem\u003et\u003c/em\u003e‑test, whereas the Wilcoxon signed-rank test was applied to non-normally distributed data. When comparing the four groups stratified by BMI, analysis of variance was used for normally distributed data, and the Kruskal-Wallis test was employed for non-normally distributed variables. Additionally, propensity score matching (PSM) was performed to adjust for sex and age, and the propensity scores were estimated using a logistic regression model. PSM was performed using the nearest-neighbor method with a caliper of 0.10. All statistical tests were two-sided, and a p‑value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. Statistical analyses were conducted using R software (version 4.2.3).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eBaseline Characteristics of Subjects\u003c/h2\u003e \u003cp\u003eAmong the 4,718 patients who underwent screening colonoscopy, 4,699 were eligible for the study after excluding 19 patients with insufficient data. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the baseline characteristics of the 4,699 participants in the non-obese (n\u0026thinsp;=\u0026thinsp;3058, 65.1%) and obese (n\u0026thinsp;=\u0026thinsp;1 641, 34.9%) groups. Age, age group, comorbid diseases, current medication use (except antiplatelet agents), history of abdominal surgery, indications for colonoscopy, and type of preparation agent were not different between the two groups. The obese group was characterized by male predominance and more antiplatelet agent users (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline characteristics of the subjects\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBaseline characteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-obesity (BMI\u0026thinsp;\u0026lt;\u0026thinsp;25kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3,058)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eObesity (BMI\u0026thinsp;\u0026ge;\u0026thinsp;25kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.5\u0026thinsp;\u0026plusmn;\u0026thinsp;11.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.562\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge group, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.836\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt; 50 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,139 (37.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e617 (37.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;50 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,919 (62.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,024 (62.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,573 (51.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,216 (74.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1485 (48.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e425 (25.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComorbid diseases, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e141 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e91 (5.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.181\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiabetes mellitus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e140 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e87 (5.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.302\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIschemic heart disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e173 (5.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e96 (5.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.837\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCerebrovascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19 (1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.382\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCurrent medication use, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAntiplatelet agents (including aspirin)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e209 (6.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e187 (11.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnticoagulants\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (0.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (0.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.415\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-steroidal anti-inflammatory drugs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e58 (1.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41 (2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.207\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of abdominal surgery, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e630 (20.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e318 (19.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.343\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndication of colonoscopy, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eScreening/surveillance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3,058 (100.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,641 (100.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of preparation agents, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.185\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1L PEG/Asc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,360 (44.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e696 (42.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOral sulfate tablet\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,698 (55.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e945 (57.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eBMI, body mass index; SD, standard deviation; PEG/Asc, polyethylene glycol/ascorbic acid.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eQuality of Preparation and Colonoscopy Outcomes\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the bowel preparation quality and colonoscopy outcomes before and after PSM. The quality of bowel preparation measured by the efficacy of preparation in each segment with BBPS, overall high-quality cleaning, overall successful cleansing, and rate of colonoscopy termination due to inadequate preparation were not significantly different between the non-obese and obese groups before and after PSM.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBowel preparation quality and colonoscopy outcomes before and after propensity score matching\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eBefore PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003eAfter PSM\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-obesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3,058)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eObesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNon-obesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eObesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuality of bowel preparation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEfficacy of preparation (BBPS), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal score (0\u0026ndash;9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.325\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.717\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight-sided colon (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.937\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTransverse colon (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.582\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.419\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft-sided colon (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.404\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.913\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh-quality cleansing, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,618 (52.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8,39 (51.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.256\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e852 (51.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e839 (51.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.675\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuccessful cleansing, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,823 (92.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,516 (92.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.980\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1,519 (92.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1,516 (92.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.895\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTermination due to inadequate prep, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.817\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.717\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColonoscopy outcome, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCecal intubation rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (0.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.610\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePolyp detection rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,574 (51.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e986 (60.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e887 (54.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e986 (60.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAdenoma detection rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,004 (32.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e644 (39.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e567 (34.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e644 (39.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColorectal cancer detection rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003ePSM, propensity score matching; BBPS, Boston Bowel Preparation Scale; SD, standard deviation\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ea\u003c/sup\u003ePropensity score matched for age and sex.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe overall successful cleaning rate was 92.3%, the overall cecal intubation rate was 99.9%, and the overall ADR of 35.1% in this study indicates high-quality colonoscopy. Cecal intubation and detection rates of CRC were not significantly different between the non-obese and obese groups before and after PSM. PDR and ADR were higher in the obese group than in the non-obese group before PSM (both \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). After PSM, the PDR and ADR were also significantly higher in the obese group than in the non-obese group (60.1% \u003cem\u003evs\u003c/em\u003e. 54.1%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001, and 39.2% \u003cem\u003evs\u003c/em\u003e. 34.6%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.006, respectively).\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eQuality of Preparation and Colonoscopy Outcomes According to BMI\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows quality of bowel preparation and colonoscopy outcomes according to BMI subgroups after PSM. The quality of bowel preparation measured by efficacy of preparation in each segment with BBPS, overall high-quality cleaning, overall successful cleansing, and rate of colonoscopy termination due to inadequate preparation, were not significantly different according to BMI subgroups. PDR and ADR were increased significantly in proportion as BMI increased (both p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In addition, cecal intubation rate and detection rate of CRC was not significantly different according to BMI subgroups.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eQuality of preparation and colonoscopy outcomes according to body mass index (after propensity score matching\u003csup\u003ea\u003c/sup\u003e)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eBody mass index group\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUnderweight (n\u0026thinsp;=\u0026thinsp;62)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNormal\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;842)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOverweight\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;737)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eObesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuality of bowel preparation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEfficacy of preparation (BBPS), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal score (0\u0026ndash;9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.854\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight-sided colon (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.992\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTransverse colon (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.738\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft-sided colon (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.346\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh quality cleansing (all segment\u0026thinsp;\u0026ge;\u0026thinsp;3), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32 (51.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e443 (52.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e377 (51.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e839 (51.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.909\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuccessful cleansing (all segment\u0026thinsp;\u0026ge;\u0026thinsp;2), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e58 (93.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e779 (92.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e682 (92.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1,516 (92.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.988\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTermination due to inadequate prep, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.813\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColonoscopy outcome, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCecal intubation rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.813\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePolyp detection rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 (48.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e424 (50.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e433 (58.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e986 (60.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAdenoma detection rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (24.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e269 (31.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e283 (38.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e644 (39.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColorectal cancer detection rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.813\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003ePSM, propensity score matching; BBPS, Boston Bowel Preparation Scale; SD, standard deviation\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003ea\u003c/sup\u003ePropensity score matched for age and sex.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003eb\u003c/sup\u003eBody mass index group was defined as underweight (\u0026lt;\u0026thinsp;18.5 kg/m\u003csup\u003e2\u003c/sup\u003e), normal (18.5\u0026ndash;22.9 kg/m\u003csup\u003e2\u003c/sup\u003e), overweight (23.0-24.9 kg/m\u003csup\u003e2\u003c/sup\u003e), and obesity (\u0026ge;\u0026thinsp;25 kg/m\u003csup\u003e2\u003c/sup\u003e).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eLaboratory Data\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows laboratory data on the day of colonoscopy. The proportion of participants with abnormal potassium and calcium levels was significantly higher in the non-obese group than in the obese group. However, the actual numerical differences were negligible and subclinical in all the cases.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLaboratory data on day of colonoscopy according to obesity (after propensity score matching\u003csup\u003ea\u003c/sup\u003e)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLaboratory data\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-obesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eObesity\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1,641)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN (mg/dL), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.881\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBeyond NR (6\u0026ndash;20), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e78 (4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77 (4.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium (mEq/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e140.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e140.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.699\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBeyond NR (136\u0026ndash;145), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50 (4.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e51 (4.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mEq/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBeyond NR (3.5\u0026ndash;5.1), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61 (5.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38 (3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChloride (mEq/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e102.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e102.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.098\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBeyond NR (98\u0026ndash;107), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e139 (14.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e111 (11.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.026\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCalcium (mg/dL), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBeyond NR (9.1\u0026ndash;10.6), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e133 (8.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89 (5.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePhosphorus (mg/dL), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBeyond NR (2.5\u0026ndash;4.5), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e197 (12.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e174 (10.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.223\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eBUN, blood urea nitrogen; SD, standard deviation; NR, normal range.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003ePropensity score matched for age and sex.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eTo the best of our knowledge, this is the largest study on the quality of bowel preparation in non-obese and obese subjects from Asian populations. In this study, the quality of bowel preparation measured by the efficacy of preparation in each segment with BBPS, overall high-quality cleaning, overall successful cleansing, and rate of colonoscopy termination due to inadequate preparation were not significantly different between the non-obese and obese groups as well as the BMI subgroups. Our study supports the finding that obesity and BMI are not related to inadequate bowel preparation, which is consistent with previous Western studies [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePrevious reports supporting the positive association between obesity and inadequate bowel preparation leaved much room for debate due to many limitations [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. American guideline [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] published on bowel preparation stated that obesity might be a possible predictor of inadequate bowel preparation based on two previous studies [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Borg \u003cem\u003eet al.\u003c/em\u003e showed that BMI\u0026thinsp;\u0026ge;\u0026thinsp;25 kg/m\u003csup\u003e2\u003c/sup\u003e is an independent risk factor of inadequate bowel preparation in a retrospective study of 1588 subjects [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, this study was limited, as it included only 58.4% of screening/surveillance colonoscopies with variable indications, such as gastrointestinal bleeding (21.5%) and constipation (12.1%). In addition, 87.0% of the participants used PEG without reporting patient compliance. Fayad \u003cem\u003eet al\u003c/em\u003e. also showed that BMI\u0026thinsp;\u0026ge;\u0026thinsp;30 kg/m\u003csup\u003e2\u003c/sup\u003e was an independent risk factor for inadequate preparation in retrospective study of 2163 subjects [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. This study also included only 68.7% of screening/surveillance indications. In addition, 91.1% of the subjects used 4 L PEG without reporting patient compliance. A retrospective cohort study with 1082 subject also reported that obesity was significantly associated with inadequate bowel preparation [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, this study was also limited as 13.3% of diagnostic colonoscopy was included and variable bowel preparation agents were used, such as 4 L PEG, picoprep and other agents. Compared with these studies [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], our current study was characterized by 100% screening colonoscopy and 100% use of low-volume agents. More recently, European guidelines published in 2019 did not state an association between obesity and bowel preparation [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThere is no evidence in the current literature supporting a physiological explanation for the potential association between obesity and bowel preparation quality. It is possible that patient compliance is responsible for the inconsistent results of previous studies. Noncompliance with preparation instructions may be higher among obese subjects and therefore may be a reason for the positive association between obesity and the quality of bowel preparation. This may explain the negative association between obesity and bowel preparation quality when low-volume agents were used in previous studies [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] and in the current study. However, no association was reported between obesity and bowel preparation using 4 L PEG in three prospective studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] and a retrospective study [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Many previous studies evaluated the association between obesity/BMI and the quality of bowel preparation using the Aronchick scale [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], which is subjective and variable in adequacy of preparation assessment. Only one prospective study [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] that used a validated BBPS, similar to our study, showed no association between the quality of preparation and obesity. Therefore, growing evidence, including that of the current study, supports no association between obesity/BMI and the quality of bowel preparation.\u003c/p\u003e \u003cp\u003eWe also found that PDR and ADR were significantly higher in the obese group than in the non-obese group after PSM for age and sex, which are well-known risk factors for colorectal neoplasia (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.006, respectively). In addition, PDR and ADR increased significantly in proportion as BMI increased (both p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). These findings are consistent with many previous studies that obesity is associated with increased detection of colorectal precursor lesions [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. In a large population-based study from Poland, obesity was associated with higher ADR than normal weight group (22.03% \u003cem\u003evs\u003c/em\u003e 17.11%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In a systemic review and meta-analysis, obesity (BMI\u0026thinsp;\u0026ge;\u0026thinsp;30 kg/m\u003csup\u003e2\u003c/sup\u003e) was a significant risk factor for colorectal adenoma with a pooled odd ratio of 1.47 (95% confidence interval\u0026thinsp;=\u0026thinsp;1.18\u0026ndash;1.83) [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur study is the largest Asian study focusing on the quality of bowel preparations associated with obesity and BMI during screening colonoscopy. Despite the retrospective design, the colonoscopy quality in this study was excellent, with was represented by 92.3% overall successful cleaning rate of 99.9% overall cecal intubation rate of 35.1% overall ADR. In addition, detailed clinical information, including comorbidities and medication history, was obtained from the health check-up data. Despite these strengths, this study had several limitations. First, we could not assess patient compliance, even though low-volume agents were used, because of the retrospective nature of the study. However, the tolerability of 1 L PEG/Asc and OST was excellent in clinical trials. Second, our findings may not be generalizable to other populations as our subjects were relatively healthy individuals who underwent medical checkups. Therefore, baseline characteristics of the study population may differ from those of the general population. Third, given the differences in obesity definition between Asian and Western populations [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], obesity was defined as a BMI\u0026thinsp;\u0026ge;\u0026thinsp;25 Kg/m\u003csup\u003e2\u003c/sup\u003e in this study. This distinction in obesity thresholds has been widely acknowledged in many studies related to obesity. Finally, only 1 L of PEG/Asc and OST were used in this study; therefore, other low-volume agents should be evaluated in future studies.\u003c/p\u003e \u003cp\u003eIn conclusion, this study showed that obesity and BMI were not associated with suboptimal bowel preparation for colonoscopy using low-volume agents. In addition, PDR and ADR were significantly higher in the obese group than in the non-obese group. Prospective studies using low-volume agents are warranted to confirm these findings.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eSupplementary Information\u003c/strong\u003e The online version contains supplementary material available at\u0026nbsp;https:// doi. org/\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e The authors thank Hyo Been Lee for statistical analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e JMC contributed toward conceptualization, interpretation, draft of manuscript, and review of manuscript; HIC contributed toward acquisition of the data, analysis of the data, interpretation, and review of manuscript; and ML contributed toward conceptualization, acquisition of the data, analysis of the data, interpretation, draft of manuscript, and review of manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e None.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e No datasets were generated or analyzed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e The authors have nothing to disclose and have no potential conflicts.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOpen Access\u003c/strong\u003e This article is\u0026nbsp;licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, which permits any non-commercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eRex DK, Boland CR, Dominitz JA, et al. Colorectal cancer screening: Recommendations for physicians and patients from the US multi-society task force on colorectal cancer. Gastroenterology. 2017;153:307\u0026ndash;323.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmitay EL, Niedermaier T, Gies A, Hoffmeister M, Brenner H. Risk factors of inadequate bowel preparation for screening colonoscopy. J Clin Med. 2021;10:2740.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBorg BB, Gupta NK, Zuckerman GR, Banerjee B, Gyawali CP. Impact of obesity on bowel preparation for colonoscopy. Clin Gastroenterol Hepatol. 2009;7:670\u0026ndash;675.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFayad NF, Kahi CJ, El-Jawad KHA, et al. Association between body mass index and quality of split bowel preparation. Clin Gastroenterol Hepatol. 2013;11:1478\u0026ndash;1485.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaurie BD, Teoh MMK, Noches-Garcia A, Nyandoro MG. Colonic bowel prep and body mass index: dose one size fit all? A multi-centre review. Int J Colorectal Dis. 2022;37:2451\u0026ndash;2457.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnklesaria AB, Ivanina EA, Chudy-Onwugaje KO, et al. The effect of obesity on the quality of bowel preparation for colonoscopy: results from a large observational study. J Clin Gastroenterol. 2019;53:e214-e220.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharara A, Harb AH, Sarkis FS, Chalhoub JM, Habib RH. Body mass index and quality of bowel preparation: real life vs clinical trials. Arab J Gastroenterol. 2016;17:11\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHookey L, Bertiger G, Johnson 2nd KL, Boules M, Ando M, Dahdal DN. Efficacy, safety, and tolerability of a read-to-drink bowel preparation in overweight and obese adults: subanalysis by body mass index from a phase III, assessor-blinded study. Therap Adv Gastroenerol. 2020;13:1756284820910050.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark SB, Lee MH, Kwak MS, Cha JM. Acute gastropathy associated with bowel preparation for colonoscopy. Korean J Gastroenterol. 2024;84:82\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHaam JH, Kim BT, Kim EM, et al. Diagnosis of obesity: 2022 update of clinical practice guidelines for obesity by the Korean Society for the Study of Obesity. J Obes Metab Syndr. 2023;32:121\u0026ndash;129.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLai EJ, Calderwood AH, Doros G, Fix OK, Jacobson BC. The Boston bowel preparation scale: a valid and reliable instrument for colo noscopy-oriented research. Gastrointest Endosc. 2009;69(3 Pt 2):620\u0026ndash;625.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalderwood AH, Jacobson BC. Comprehensive validation of the Boston Bowel Preparation Scale. Gastrointest Endosc. 2010;72: 686\u0026ndash;692.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKwak MS, Cha JM, Yang HJ, et al. Safety and efficacy of low-vol ume preparation in the elderly: oral sulfate solution on the day before and split-dose regimens (SEE SAFE) study. Gut Liver. 2019;13:176\u0026ndash;182.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJung Y, Kang SB, Yoon HJ, Cha JM. Improving the tolerability and safety of 1-L polyethylene glycol plus low-dose ascorbic acid for bowel preparation in a healthy population: a randomized multicenter clinical trial. Gastrointest Endosc. 2022;96:341\u0026ndash;350.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnson DA, Barkun AN, Cohen LB, et al. Optimizing adequacy of bowel cleansing for colonoscopy: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer. Gastrointest Endosc. 2014;80:543\u0026ndash;56\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHassan C, East J, Radaelli F, et al. Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESE) guideline \u0026ndash; update 2019. Endoscopy. 2019;51:775\u0026ndash;794.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFok KC, Turner IB, Teoh WC, et al. Obesity does not affect sodium picosulphate bowel preparation. Intern Med J. 2012;42: 1324\u0026ndash;1329.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChung YW, Han DS, Park KH, et al. Patient factors predictive of inadequate bowel preparation using polyethylene glycol: a prospective study in Korea. J Clin Gastroenterol. 2009;43:448\u0026ndash;452.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNess RM, Manam R, Hoen H, et al. Predictors of inadequate bowel preparation for colonoscopy. Am J Gastroenterol. 2001; 96:1797\u0026ndash;1802.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGovani SM, Elliott EE, Menees SB, et al. Predictors of suboptimal bowel preparation in asymptomatic patients undergoing average-risk screening colonoscopy. World J Gastrointest Endosc. 2016;8:616\u0026ndash;622.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKobiela J, Wieszczy P, Regula J, Kaminski M. Association of obesity with colonic findings in screening colonoscopy in a large population-based study. United European Gastroenterol J. 2018;6:1538\u0026ndash;1546.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOmata F, Deshpande GA, Ohde S, Mine T, Fukui T. The association between obesity and colorectal adenoma: systematic review and meta-analysis. Scand J Gastroenterol. 2013;48:136\u0026ndash;146.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"digestive-diseases-and-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ddsj","sideBox":"Learn more about [Digestive Diseases and Sciences](http://link.springer.com/journal/10620)","snPcode":"10620","submissionUrl":"https://submission.nature.com/new-submission/10620/3","title":"Digestive Diseases and Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Adenoma, Body mass index, Cathartics, Colonoscopy, Obesity","lastPublishedDoi":"10.21203/rs.3.rs-6521515/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6521515/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eObesity and body mass index (BMI) have been reported as risk factors associated with inadequate bowel preparation, however, conflicting results have been consistently reported. This study aims to explore the association between obesity and the quality of bowel preparation.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003e We evaluated the efficacy of bowel preparation and colonoscopy outcomes according to obesity and BMI in subjects who underwent screening colonoscopy at a single hospital between January 1, 2021, and December 31, 2022. Overall, the quality of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe 4,699 subjects who underwent screening colonoscopy were classified as the non-obese (n\u0026thinsp;=\u0026thinsp;3,058, 65.1%) and obese (n\u0026thinsp;=\u0026thinsp;1, 641, 34.9%) groups. The quality of bowel preparation measured by the efficacy of preparation in each segment, overall high-quality cleaning and successful cleansing, and rate of colonoscopy termination due to inadequate preparation were not significantly different between the non-obese and obese groups and according to BMI subgroups. Polyp and adenoma detection rates were significantly higher in the obese group than in the non-obese group after propensity score matching for age and sex, which are well-known risk factors for colorectal neoplasia (60.1% \u003cem\u003evs\u003c/em\u003e 54.1%, p\u0026thinsp;=\u0026thinsp;0.001 and 39.2% \u003cem\u003evs\u003c/em\u003e 34.6%, p\u0026thinsp;=\u0026thinsp;0.006, respectively).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eObesity and BMI were not associated with suboptimal preparation for colonoscopy when low-volume agents were used. In addition, polyp and adenoma detection rates were significantly higher in the obese group than in the non-obese group.\u003c/p\u003e","manuscriptTitle":"Obesity and Body Mass Index are Not Associated with Suboptimal Quality of Bowel Preparation for Colonoscopy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-06 16:08:44","doi":"10.21203/rs.3.rs-6521515/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-18T22:19:35+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-16T04:29:02+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-09T09:34:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"46047258352263654976583158966698129253","date":"2025-05-03T08:17:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"235833375310603732425236155187463665460","date":"2025-05-02T10:37:25+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-02T08:24:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"210028923556982349399047186576772118058","date":"2025-05-01T00:51:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"299774007168731981190148942621090519428","date":"2025-05-01T00:13:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-30T10:29:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-28T19:00:30+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-24T14:18:59+00:00","index":"","fulltext":""},{"type":"submitted","content":"Digestive Diseases and Sciences","date":"2025-04-24T14:04:48+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"digestive-diseases-and-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ddsj","sideBox":"Learn more about [Digestive Diseases and Sciences](http://link.springer.com/journal/10620)","snPcode":"10620","submissionUrl":"https://submission.nature.com/new-submission/10620/3","title":"Digestive Diseases and Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"82ad349c-8ad5-48ae-8ffa-3a927eaad3b2","owner":[],"postedDate":"May 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-07-07T16:11:51+00:00","versionOfRecord":{"articleIdentity":"rs-6521515","link":"https://doi.org/10.1007/s10620-025-09195-5","journal":{"identity":"digestive-diseases-and-sciences","isVorOnly":false,"title":"Digestive Diseases and Sciences"},"publishedOn":"2025-07-01 15:58:09","publishedOnDateReadable":"July 1st, 2025"},"versionCreatedAt":"2025-05-06 16:08:44","video":"","vorDoi":"10.1007/s10620-025-09195-5","vorDoiUrl":"https://doi.org/10.1007/s10620-025-09195-5","workflowStages":[]},"version":"v1","identity":"rs-6521515","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6521515","identity":"rs-6521515","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}