2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients

2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article 2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients Zhe Xiong, Ying Fang, Fangfang Feng, Yiming Cheng, Huahui Zhang, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1852987/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objectives : The study aimed to compare the cleansing effect, compliance and adverse of polyethylene glycol 2L with castor oil and polyethylene glycol 4L on bowel preparation prior to colonoscopy in inpatients. Methods : Our study retrospectively analyzed the medical records and colonoscopy reports of inpatients (n=673) who underwent colonoscopy at the Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University, and the inpatients were divided into two groups according to different bowel preparation protocols. BBPS is used to assess the degree of bowel cleanliness before colonoscopy. We statistically analyzed and compared the degree of bowel cleansing between 2L-PEG-CaO and 4L-PEG group, as well as the compliance and adverse effects of the medication in both groups. Results : Among 673 patients undergoing colonoscopy, 330 were prescribed 4L-PEG and 343 2L-PEG-CAO. Both groups of inpatients were matched for baseline characteristics. In the 4L-PEG and 2L-PEG-CaO groups, adequate bowel preparation rate was 72.4% and 77.3% ( P =0.148), BBPS scores was 6.79±1.51 and 7.03±1.71 ( P =0.056), and adverse event rate was 68.2% and 30.0% ( P <0.001), respectively. Conclusion : The 2L-PEG combined with castor oil is an effective and safe cleansing regimen for bowel preparation and is relatively inexpensive and suitable for wider use. castor oil bowel preparation polyethylene glycol colonoscopy inpatients Introduction The incidence of rectal cancer, one of the most common cancers worldwide, has recently shown an upward trend in Asian countries, posing a huge burden on healthcare[ 1 ]. Colonoscopy is the most effective method for early diagnosis and prevention of colorectal cancer[ 2 ]. As is known to all, adequate bowel preparation is a key part of colonoscopy as it effectively improves the diagnostic performance of the test[ 3 – 5 ]. Inadequate bowel preparation often results in increased missed diagnosis of precancerous and cancerous lesions, prolonged procedure time, suboptimal cecum insertion rates, and increased risk of complications[ 6 ]. Patients with inadequate bowel preparation have increased hospitalization rates, which can negatively impact patient tolerance and healthcare costs. Inpatient status has been identified as a well-known risk factor for inadequate colon cleansing, and in fact about 50–70% of inpatients achieving a competent colon cleansing, which is still a long way from our imagined threshold of 90%[ 7 , 8 ]. In addition, inpatients are often considered to be "hard-to-prepare"[ 9 ], so many researchers have recently investigated ways to improve bowel cleansing in inpatients, such as face-to-face instruction for patients with risk factors for inadequate bowel preparation[ 10 ]. To date, polyethylene glycol (PEG) solutions have become the most common protocol prior to colonoscopy[ 11 ]. However, standard 4l high volumes of PEG reduce patient tolerance and compliance[ 12 ]. Therefore, to reduce the volume of fluid required, researchers combine PEG with ascorbic acid or bisacodyl to improve inpatient compliance[ 11 , 13 ]. Even so, this is still a long way from the quality we expect from bowel preparation, it is therefore always worth exploring how to improve the quality of bowel preparation prior to colonoscopy in inpatients. There is still some controversy regarding studies on reducing the volume of fluid in conventional 4LPEG in order to reduce the amount of fluid consumed by patients to increase patient tolerance. In a single-center, randomized controlled study, their team found that 4L-PEG was superior to 36 mg senna and 2L-PEG as colon cleaning prior before colonoscopy[ 14 ]. But there are also studies that show that 2L PEG in combination with bisacodyl[ 15 ] or in combination with sodium phosphate (NaP)[ 16 ] also gives the desired bowel cleansing effect, reduces the volume of fluid required and increases patient tolerance and willingness to repeat the preparation when compared to the standard 4L PEG regimen. Castor oil (CaO) has been found to be a safe and effective stimulant laxative and has been proved to be very effective in colon cleansing. For example, Yang et al.[ 17 ] suggested that castor oil and bisacodyl were comparable in their laxative efficacy. However, few studies have used castor oil in the preparation of the bowel prior to colonoscopy in inpatients. In this regard, in inpatients, we used 2L PEG combined with castor oil regimen for bowel preparation, observed the effectiveness of this regimen, and tolerance of patient, and compared this regimen with traditional 4L-PEG, aiming to find better bowel preparation methods. Materials And Methods Data sources We conducted a retrospective cohort analysis of data collected form inpatients with underwent colonoscopy at the Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University from June 2020 to December 2021. Inclusion criteria: (1) inpatients undergoing colonoscopy for any indication; (2) colonoscopy in the early morning; (3) age ≥ 18 years; (4) complete medical history. Exclusion criteria: (1) inpatients undergoing EMR (endoscopic mucosal resection)/ESD (endoscopic submucosal dissection); (2) Outpatients undergoing bowel preparation outside the hospital; (3) Unable to undergo bowel preparation for various reasons; (4) Missing medical records. In addition, we collected medical information of inpatients from the hospital electronic case system, including age, gender, height, weight, BMI, reason for colonoscopy, comorbidities, number of days in hospital prior to colonoscopy and Boston Bowel Preparation Scale (BBPS). All inpatients were divided into two groups, one with 2L PEG plus castor oil for bowel preparation and the other with a 4L PEG regimen. All patients received intensive bowel preparation instructions for bowel preparation during hospitalization. Briefly, the inpatient is guided by the ward nurse or doctor in bowel preparation before colonoscopy. Patients in the 2L-PEG-Cao group were asked to take 40ml of castor oil at 8:00 p.m. the day before colonoscopy; on the day of procedure, they took 2L PEG (each liter containing 64g polyethylene glycol 4000, 1.46g sodium chloride, 5.7g sodium sulfate, 0.75g potassium chloride, 1.68g sodium bicarbonate) at 7:00-8:00 a.m. before colonoscopy, at a rate of 250 ml every 15 min. Patients in the 4L-PEG group were asked to begin to drink the first 2L of PEG at 7:00-8:00 p.m. on the day before colonoscopy, on the day of procedure, they took the other 2L PEG 4-6h before colonoscopy. Encourage patients to drink extra clear liquid after taking laxatives to hydrate adequately before colonoscopy. All patients were asked to eat a low-residue or clear liquids food on the day of colonoscopy. Primary Outcome Colonoscopies of all patients were performed by the five senior endoscopists at the Gastroenterology Centre, each of them had performed at least 1000 colonoscopies. They assessed bowel cleanliness in segments based on the Boston Bowel Preparedness Scale (BBPS): 0 = More solid or semi-solid stool remains, intestinal mucosa not clearly visible; 1 = Some of the bowel mucosa is clearly visible, most of it is still not clearly visible due to staining, faecal masses or opaque mucus residue; 2 = A small amount of staining, granular stool or opaque mucous residue, but does not affect the clear exposure of intestinal mucosa; 3 = No staining, faecal or opaque mucus residue, the intestinal mucosa is completely visible. Segmental method: right colon (cecum to ascending colon), transverse colon (including hepatic and splenic flexures), left colon (descending colon and rectum)[18]. All bowel segment scores were added together for a total score, with higher scores indicating better quality bowel preparation. Adequate bowel preparation was defined as a total BBPS score was ≥6, and a score was ≥2 for each segment. Safety Assessments We collected the actual amount of PEG solution taken by the patients in nursing records, and the dosage ≥80% indicated good compliance of patients. The nursing sheet also recorded whether nausea and/or vomiting, abdominal pain, abdominal distension and other adverse reactions occurred during the intestinal process. Statistical Analysis SPSS 25.0 for Windows (SPSS, Chicago, Illinois, USA) was used to analyze all data. Continuous variables were expressed as mean ± standard deviation (SD), and discontinuous variables were expressed as counts and percentages. Comparisons between groups were made using the Student t -test, data for categorical variables were tested using chi-square or Fisher exact test. The P values < 0.05 were considered statistically significant. Results Baseline Characteristics We consulted case information from 673 patients, and according to different protocols for bowel preparation prior to colonoscopy. We divided patients into two groups, 330 patients received 4L PEG and 343 patients received 2L PEG plus 40ml castor oil. There were no significant differences in baseline characteristics between the two groups in terms of age, gender, weight, BMI, length of stay in hospital prior to colonoscopy, medical status, or colonoscopy indicators ( P > 0.05)( Table 1 ). Table 1 Characteristics of the patients. 4-PEG(n = 330) 2-PEG-CaO(n = 343) P -value Age (mean ± SD, years) 56.55 ± 12.27 56.08 ± 13.08 0.627 Sex, n (%) 0.766 Male 176(53.3) 179(52.2) Female 154(46.7) 164(47.8) Height (mean ± SD, cm) 165.58 ± 7.27 164.79 ± 7.19 0.156 Weight (mean ± SD, kg) BMI (mean ± SD, kg) Days in hospital (mean ± SD, days) 62.54 ± 11.37 22.72 ± 3.33 3.79 ± 1.53 63.146 ± 10.48 23.20 ± 3.06 3.64 ± 1.49 0.470 0.051 0.175 Medical condition, n (%) NO Hypertension Diabetes mellitus Cardiovascular disease Hyperlipidemia Inflammatory Bowel Diseases Previous abdominal surgery Others Indication for colonoscopy, n (%) Abdominal pain Diarrhea Constipation Occult blood in stool Anemia Physical examination Others 144(43.6) 113(34.2) 54(16.4) 16(4.8) 41(12.4) 23(7.0) 103(31.2) 57(17.3) 85(25.8) 52(15.8) 14(4.2) 33(10) 9(2.7) 82(24.8) 55(16.7) 164(47.8) 105(30.6) 42(12.2) 13(3.8) 33(9.6) 32(9.3) 89(25.9) 42(12.2) 79(23.0) 57(16.6) 21(6.1) 45(13.1) 6(1.7) 95(27.7) 42(12.2) 0.277 0.314 0.127 0.499 0.245 0.264 0.131 0.660 0.410 0.762 0.272 0.206 0.390 0.401 0.103 PEG, polyethylene glycol; CaO, castor oil Comparison of colonoscopy results The rates for adequate bowel preparation in the 4L-PEG and 2L-PEG-CaO groups were 72.4% and 77.3%, respectively, with no statistically significant difference between the two groups ( P = 0.148). In addition, the rates of polyp detection were 30.9% and 35.9%, adenoma detection were 13.0% and 14.9%, cancer detection were 2.7% and 4.1%, and colitis detection were 26.4% and 22.2%, respectively, between the two groups, with no statistically significant differences between the two groups( P > 0.05) ( Table 2 ). Table 2 Comparison of colonoscopy results 4-PEG(n = 330) 2-PEG-CaO(n = 343) P -value Adequate bowel preparation, n (%) 239(72.4) 265(77.3) 0.148 Medical results, n (%) Normal Polyps Adenoma Cancer Colitis 74(22.4) 102(30.9) 43(13.0) 9(2.7) 87(26.4) 57(16.6) 123(35.9) 51(14.9) 14(2.1) 76(22.2) 0.057 0.174 0.492 0.334 0.203 Others 15(4.5) 22(6.4) 0.288 PEG, polyethylene glycol; CaO, castor oil Comparison of Boston Bowel Preparation Scores There was no significant difference between the two groups in terms of scoring the quality of bowel preparation, with a mean (SD) total score of 6.79 ± 1.51 for the 4L-PEG group and 7.03 ± 1.71 for 2L-PEG-Cao group ( P = 0.056). The analysis of the segmental (right, transverse, and left colon) BBPS scale showed no difference for the right side (2.22 ± 0.79 vs 2.26 ± 0.71) and transverse colon (2.26 ± 0.68 vs 2.34 ± 0.68). However, the left colon score was significantly higher in the 2L-PEG-CaO group than in the 4L-PEG group (2.41 ± 0.68 vs 2.31 ± 0.59, P = 0.038). Table 3 presents the results of bowel cleansing quality assessment based on the BBPS. Table 3 Comparison of Boston bowel preparation score between the two groups 4-PEG(n = 330) 2-PEG-CaO(n = 343) P -value Right side of colon (mean ± SD) 2.22 ± 0.79 2.26 ± 0.71 0.475 Mid colon (mean ± SD) 2.26 ± 0.68 2.34 ± 0.68 0.141 Left side of colon (mean ± SD) 2.31 ± 0.59 2.41 ± 0.68 0.038 BBPS (mean ± SD) 6.79 ± 1.51 7.03 ± 1.71 0.056 PEG, polyethylene glycol; CaO, castor oil Comparison of Patient Compliance and Adverse Effects Table 4 shows the incidence of bowel preparation-related adverse events, including nausea/vomiting, abdominal pain, and bloating. There was a statistical difference between the two groups in terms of nausea/vomiting and abdominal distention ( P < 0.001). The incidence of abdominal pain in the 2L-PEG-CaO group was higher than that in the 4L-PEG group. However, the difference was not statistically significant ( P = 0.324). The 2L-PEG-CaO group reported fewer overall adverse events than the 4L-PEG group ( P < 0.001). Table 4 Comparison of adverse reactions between the two groups 4-PEG(n = 330) 2-PEG-CaO(n = 343) P -value Nausea/Vomiting, n (%) 62(18.8) 19(5.5) < 0.001* Abdominal pain, n (%) 53(16.1) 65(19.0) 0.324 Bloating, n (%) 98(29.7) 31(9.0) < 0.001* Total, n (%) 213(64.5) 115(33.5) < 0.001* PEG, polyethylene glycol; CaO, castor oil, * P < 0.05 Discussion Early screening for colon cancer is the most effective method to reduce the prevalence and mortality of colorectal cancer. Colonoscopy is an important tool for diagnosing and screening colon lesions, and ideal bowel preparation is an important step to complete the colonoscopy[ 19 ]. The ideal bowel preparation method not only needs to clean the bowel effectively, but also needs to be easily accepted by the patient[ 20 ]. It is well known that the inpatient status has been identified as a risk factor for inadequate bowel preparation[ 21 ]. Our study found that about 30% of patients had inadequate bowel preparation, which may affect the detection rate of colon polyps and neoplasms and increase the need for repeat testing[ 22 ]. Patients may also have increased hospital stay and costs as a result. Studies have identified factors affecting bowel cleansing in inpatients[ 7 , 8 ]. We cannot improve the quality of bowel preparation by changing in patient with complications such as diabetes or the length of hospital stay before colonoscopy. However, bowel cleansing can be improved by modifying the dosing regimen of bowel preparation and the type of bowel preparation. It is worth noting that the main method of high quality colonoscopy in the outpatient setting is by means of a split-dose approach[ 4 , 5 ], which is equally widely implemented in clinical practice in inpatients. It is generally accepted that "hard-to-prepare" patients need at least 4 liters of solution, and possibly more[ 23 ]. However, a clinical study suggested that high-volume regimens are no better than low-volume regimens for patients at risk of poor bowel cleansing[ 9 ]. According to the current study, low-volume PEG combined with bisacodyl is a more suitable option for patients with a history of colon resection[ 24 ]. Similarly, in patients with constipation, reinforced low volume PEG and high volume PEG have similar bowel cleansing effects[ 25 ]. These findings are strongly correlated, in large part because low-volume bowel preparation increases patient tolerance and reduces the negative impact of the patient experience[ 26 ]. In our study, we compared 2L PEG plus castor oil preparation with the standard-of-care 4L PEG preparation between bowel cleansing quality and inpatient tolerability, with the aim of finding a better bowel preparation method. The mechanism of castor oil to clean the intestinal tract is that after oral administration of castor oil, it is decomposed into ricinoleic acid in the duodenum, which stimulates the small intestine and promotes its peristalsis and excretion, thereby inducing a strong laxative effect[ 27 , 28 ]. Studies have found that after orally taken a large dose 50 or 60 ml of castor oil, the incidence of adverse reactions such as abdominal cramping, bloating, nausea, vomiting, syncope, and coma increases in patients[ 29 , 30 ]. However, low doses of castor oil do not cause serious side effects and it has therefore become widely available as a safe stimulant laxative[ 17 , 31 , 32 ], except for pregnant women[ 33 ]. There is evidence that 30ml of castor oil reduces the amount of bowel preparation solution that can be prepared[ 34 ]. In response, In order to increase the conductivity of castor oil in bowel preparation within safety limits, we designed a bowel preparation protocol of 2L PEG combined with 40ml castor oil. Our study found, according to the BBPS results, the quality of left colon cleansing using 2L PEG combined with castor oil was significantly higher than that of traditional 4L PEG regimen, but the quality of whole colon cleansing was similar. 2L PEG combined with castor oil for bowel preparation achieved the same cleanse results as the standard 4L PEG regimen. However, the 2L-PEG-CaO regimen was significantly lower than the 4L-PEG regimen in terms of the incidence of adverse events (e.g. nausea/vomiting, abdominal distension). In addition, the medical cost of the 2L-PEG-CaO regimen was also lower than that of the 4L-PEG regimen. Therefore, the 2L-PEG-CaO regimen greatly increases patient satisfaction and compliance. From our research results, the incidence of abdominal pain in the 2L-PEG-CaO regimen is higher than that in the 4L-PEG regimen. In this regard, we consider that the moderate dose of castor oil is related to the increase in intestinal peristalsis. Although there was no significant difference in the incidence of abdominal pain between the two groups, we still need to pay attention to the patient's experience, and in future studies, we need to consider whether 2L PEG combined with different doses of castor oil can have similar or more effective bowel cleansing to reduce the incidence of abdominal pain in patients. Limitations We have to confess some limitations to our study. First, this is a retrospective study, and the clinical information of the patients is extracted from the medical record system, so the obtained information is prone to bias. In this regard, in the future, our team will conduct randomized controlled clinical trials in the future to verify the conclusions of this study. However, there is an advantage to this study, as the inpatients in this study underwent bowel preparation under full medical supervision, reducing confounding factors associated with poor bowel preparation, such as type of diet before colonoscopy, bowel preparation the experience of preparing and the time to start preparing. However, this study has the advantage in that, in order to reduce the confounding factors related to poor bowel preparation, such as type of diet before colonoscopy, the experience or knowledge of bowel preparation, and the time to start preparation, the hospitalized patients of this study under the supervised of the entire course of medical care were bowel preparation. Second, while BBBS scores are validated and widely used to evaluate bowel cleansing effects, there is a subjective judgment between each endoscopist, which may indicate a bias in the evaluation of the two methods of intestinal preparation. Third, despite our large sample size, this study is still a single-center study, so a larger study is needed to validate and generalize our conclusions. Fourth, adenoma detection rate (ADR), polyp detection rate, and colon tumor detection rate are important quality control indicators for colonoscopy screening, which were not found in the cases investigated in this study. Conclusion In conclusion, the results of this study suggest that it is safe for hospitalized patients to use 2L PEG combined with 40 ml CaO for bowel preparation before colonoscopy, it obtains the same quality of bowel preparation to traditional 4L split PEG, and it improves patient satisfaction and compliance with bowel preparation. Declarations Data Availability Statement The datasets used or analyzed during the current study are available from the corresponding author on reasonable request. Ethics Statement This retrospective study was in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University. The patients provided their written informed consent to participate in this study. Declaration of funding This work was supported by the Changzhou Second People's Hospital Fund (2019HZD001) and the Nanjing Medical University Fund (NMUC2021026A). The funders had no role in study design, data collection and analysis, publication decisions or manuscript preparation. Declaration of financial/other relationships All authors claim no conflict of interest. Author contributions ZX drafted the manuscript. JH provided design ideas for this study, and YF, FFF, YMC, HHZ, CYH participated in data analysis and supplemented ideas. All authors read and approved the final manuscript. Acknowledgements Not applicable Consent to publish All authors consent to publish. References Schreuders EH, Ruco A, Rabeneck L, Schoen RE, Sung JJ, Young GP, Kuipers EJ: Colorectal cancer screening: a global overview of existing programmes . Gut 2015, 64 (10):1637–1649. Zauber AG, Winawer SJ, O'Brien MJ, Lansdorp-Vogelaar I, van Ballegooijen M, Hankey BF, Shi W, Bond JH, Schapiro M, Panish JF et al : Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths . N Engl J Med 2012, 366 (8):687–696. 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Chen CC, Ng WW, Chang FY, Lee SD: Magnesium citrate-bisacodyl regimen proves better than castor oil for colonoscopic preparation . J Gastroenterol Hepatol 1999, 14 (12):1219–1222. Bradley AJ, Taylor PM: Does bowel preparation improve the quality of intravenous urography? Br J Radiol 1996, 69 (826):906–909. Jansson M, Geijer H, Andersson T: Bowel preparation for excretory urography is not necessary: a randomized trial . Br J Radiol 2007, 80 (956):617–624. Sicuranza GB, Figueroa R: Uterine rupture associated with castor oil ingestion . J Matern Fetal Neonatal Med 2003, 13 (2):133–134. Tian X, Shi B, Liu XL, Chen H, Chen WQ: A Randomized Trial of Split Dose 3 L Polyethylene Glycol Lavage Solution, 2 L Polyethylene Glycol Lavage Combined With Castor Oil, and 1 L of Polyethylene Glycol Lavage Solution Combined With Castor Oil and Ascorbic Acid for Preparation for Colonoscopy . Front Med (Lausanne) 2019, 6 :158. Additional Declarations No competing interests reported. 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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-1852987","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":122553296,"identity":"be221690-8655-4ac7-af6c-4c3d938fdafd","order_by":0,"name":"Zhe Xiong","email":"","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zhe","middleName":"","lastName":"Xiong","suffix":""},{"id":122553297,"identity":"be655904-82ee-4d3a-849b-fc5bc90100a1","order_by":1,"name":"Ying Fang","email":"","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ying","middleName":"","lastName":"Fang","suffix":""},{"id":122553298,"identity":"8041ebd9-c988-4c96-ae3b-c9ad900f7aeb","order_by":2,"name":"Fangfang Feng","email":"","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Fangfang","middleName":"","lastName":"Feng","suffix":""},{"id":122553299,"identity":"9652d17e-1e20-4a57-8374-a094ea33c758","order_by":3,"name":"Yiming Cheng","email":"","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yiming","middleName":"","lastName":"Cheng","suffix":""},{"id":122553300,"identity":"4be39628-8829-4035-87cb-9e0f08aad7d0","order_by":4,"name":"Huahui Zhang","email":"","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Huahui","middleName":"","lastName":"Zhang","suffix":""},{"id":122553301,"identity":"8fe7d37d-4423-4cbb-8eed-500a34ac2c00","order_by":5,"name":"Chunyan Huo","email":"","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Chunyan","middleName":"","lastName":"Huo","suffix":""},{"id":122553302,"identity":"a26a0b5b-24ca-47aa-aa6f-276ba6ac4bd7","order_by":6,"name":"Jin Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6ElEQVRIie3PsQqCQBjA8TsEXY5cL4ie4RNBC8JnUQQng9ojDoTGZqGXEHqBkyNbfICDnBqahSAaIrLGBnUMuv/2Hd8PvkNIpfrBAOUManh6Jv3MdNSDCL5MFzwcpgizhpAeRPevpOY4kx+CuomLSysjUGn2KTme5WpCkCEOWRuZstIGCpeBUxVBEhfNYSSKZOthvHQAQNMcGVtJrDeEEqeLuHcfNLxP3+TZixQ+cBA4ow2Zb3oRwS0GUUhlFOzmW0r0zr/InNmPx8wz05Bf49t6bBqiaCWI8q8HvXX9nck6V1QqlerfewF7tlB0RHbvvAAAAABJRU5ErkJggg==","orcid":"","institution":"The Affiliated Changzhou NO.2 People’s Hospital of Nanjing Medical University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Jin","middleName":"","lastName":"Huang","suffix":""}],"badges":[],"createdAt":"2022-07-13 06:44:25","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1852987/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1852987/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":26632858,"identity":"954856bb-992b-4d81-b209-38e19353c90a","added_by":"auto","created_at":"2022-09-19 06:14:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1122641,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1852987/v1/2ef00aca-1669-4cb8-84c1-204ea51f5ebe.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe incidence of rectal cancer, one of the most common cancers worldwide, has recently shown an upward trend in Asian countries, posing a huge burden on healthcare[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Colonoscopy is the most effective method for early diagnosis and prevention of colorectal cancer[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. As is known to all, adequate bowel preparation is a key part of colonoscopy as it effectively improves the diagnostic performance of the test[\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Inadequate bowel preparation often results in increased missed diagnosis of precancerous and cancerous lesions, prolonged procedure time, suboptimal cecum insertion rates, and increased risk of complications[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Patients with inadequate bowel preparation have increased hospitalization rates, which can negatively impact patient tolerance and healthcare costs.\u003c/p\u003e \u003cp\u003eInpatient status has been identified as a well-known risk factor for inadequate colon cleansing, and in fact about 50\u0026ndash;70% of inpatients achieving a competent colon cleansing, which is still a long way from our imagined threshold of 90%[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In addition, inpatients are often considered to be \"hard-to-prepare\"[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], so many researchers have recently investigated ways to improve bowel cleansing in inpatients, such as face-to-face instruction for patients with risk factors for inadequate bowel preparation[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. To date, polyethylene glycol (PEG) solutions have become the most common protocol prior to colonoscopy[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, standard 4l high volumes of PEG reduce patient tolerance and compliance[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Therefore, to reduce the volume of fluid required, researchers combine PEG with ascorbic acid or bisacodyl to improve inpatient compliance[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Even so, this is still a long way from the quality we expect from bowel preparation, it is therefore always worth exploring how to improve the quality of bowel preparation prior to colonoscopy in inpatients.\u003c/p\u003e \u003cp\u003eThere is still some controversy regarding studies on reducing the volume of fluid in conventional 4LPEG in order to reduce the amount of fluid consumed by patients to increase patient tolerance. In a single-center, randomized controlled study, their team found that 4L-PEG was superior to 36 mg senna and 2L-PEG as colon cleaning prior before colonoscopy[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. But there are also studies that show that 2L PEG in combination with bisacodyl[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] or in combination with sodium phosphate (NaP)[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] also gives the desired bowel cleansing effect, reduces the volume of fluid required and increases patient tolerance and willingness to repeat the preparation when compared to the standard 4L PEG regimen. Castor oil (CaO) has been found to be a safe and effective stimulant laxative and has been proved to be very effective in colon cleansing. For example, Yang et al.[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] suggested that castor oil and bisacodyl were comparable in their laxative efficacy. However, few studies have used castor oil in the preparation of the bowel prior to colonoscopy in inpatients. In this regard, in inpatients, we used 2L PEG combined with castor oil regimen for bowel preparation, observed the effectiveness of this regimen, and tolerance of patient, and compared this regimen with traditional 4L-PEG, aiming to find better bowel preparation methods.\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cp\u003e\u003cstrong\u003eData sources\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted a retrospective cohort analysis of data collected form inpatients with underwent colonoscopy at the Affiliated Changzhou No.2 People\u0026rsquo;s Hospital of Nanjing Medical University from June 2020 to December 2021. Inclusion criteria: (1) inpatients undergoing colonoscopy for any indication; (2) colonoscopy in the early morning; (3) age \u0026ge; 18 years; (4) complete medical history. Exclusion criteria: (1) inpatients undergoing EMR (endoscopic mucosal resection)/ESD (endoscopic submucosal dissection); (2) Outpatients undergoing bowel preparation outside the hospital; (3) Unable to undergo bowel preparation for various reasons; (4) Missing medical records. In addition, we collected medical information of inpatients from the hospital electronic case system, including age, gender, height, weight, BMI, reason for colonoscopy, comorbidities, number of days in hospital prior to colonoscopy and Boston Bowel Preparation Scale (BBPS). All inpatients were divided into two groups, one with 2L PEG plus castor oil for bowel preparation and the other with a 4L PEG regimen.\u003c/p\u003e\n\u003cp\u003eAll patients received intensive bowel preparation instructions for bowel preparation during hospitalization. Briefly, the inpatient is guided by the ward nurse or doctor in bowel preparation before colonoscopy. Patients in the 2L-PEG-Cao group were asked to take 40ml of castor oil at 8:00 p.m. the day before colonoscopy; on the day of procedure, they took 2L PEG (each liter containing 64g polyethylene glycol 4000, 1.46g sodium chloride, 5.7g sodium sulfate, 0.75g potassium chloride, 1.68g sodium bicarbonate) at 7:00-8:00 a.m. before colonoscopy, at a rate of 250 ml every 15 min. Patients in the 4L-PEG group were asked to begin to drink the first 2L of PEG at 7:00-8:00 p.m. on the day before colonoscopy, on the day of procedure, they took the other 2L PEG 4-6h before colonoscopy. Encourage patients to drink extra clear liquid after taking laxatives to hydrate adequately before colonoscopy. All patients were asked to eat a low-residue or clear liquids food on the day of colonoscopy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrimary Outcome\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eColonoscopies of all patients were performed by the five senior endoscopists at the Gastroenterology Centre, each of them had performed at least 1000 colonoscopies. They assessed bowel cleanliness in segments based on the Boston Bowel Preparedness Scale (BBPS): 0 = More solid or semi-solid stool remains, intestinal mucosa not clearly visible; 1 = Some of the bowel mucosa is clearly visible, most of it is still not clearly visible due to staining, faecal masses or opaque mucus residue; 2 = A small amount of staining, granular stool or opaque mucous residue, but does not affect the clear exposure of intestinal mucosa; 3 = No staining, faecal or opaque mucus residue, the intestinal mucosa is completely visible. Segmental method: right colon (cecum to ascending colon), transverse colon (including hepatic and splenic flexures), left colon (descending colon and rectum)[18]. All bowel segment scores were added together for a total score, with higher scores indicating better quality bowel preparation. Adequate bowel preparation was defined as a total BBPS score was \u0026ge;6, and a score was \u0026ge;2 for each segment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSafety Assessments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe collected the actual amount of PEG solution taken by the patients in nursing records, and the dosage \u0026ge;80% indicated good compliance of patients. The nursing sheet also recorded whether nausea and/or vomiting, abdominal pain, abdominal distension and other adverse reactions occurred during the intestinal process.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSPSS 25.0 for Windows (SPSS, Chicago, Illinois, USA) was used to analyze all data. Continuous variables were expressed as mean \u0026plusmn; standard deviation (SD), and discontinuous variables were expressed as counts and percentages. Comparisons between groups were made using the Student \u003cem\u003et\u003c/em\u003e-test, data for categorical variables were tested using chi-square or Fisher exact test. The \u003cem\u003eP\u003c/em\u003e values \u0026lt; 0.05 were considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv class=\"Section2\" id=\"Sec8\"\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline Characteristics\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eWe consulted case information from 673 patients, and according to different protocols for bowel preparation prior to colonoscopy. We divided patients into two groups, 330 patients received 4L PEG and 343 patients received 2L PEG plus 40ml castor oil. There were no significant differences in baseline characteristics between the two groups in terms of age, gender, weight, BMI, length of stay in hospital prior to colonoscopy, medical status, or colonoscopy indicators (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05)( Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eCharacteristics of the patients.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e4-PEG(n\u0026thinsp;=\u0026thinsp;330)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2-PEG-CaO(n\u0026thinsp;=\u0026thinsp;343)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e56.55\u0026thinsp;\u0026plusmn;\u0026thinsp;12.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e56.08\u0026thinsp;\u0026plusmn;\u0026thinsp;13.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.627\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSex, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.766\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e176(53.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e179(52.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e154(46.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e164(47.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHeight (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e165.58\u0026thinsp;\u0026plusmn;\u0026thinsp;7.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e164.79\u0026thinsp;\u0026plusmn;\u0026thinsp;7.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.156\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWeight (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, kg)\u003c/p\u003e\n \u003cp\u003eBMI (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, kg)\u003c/p\u003e\n \u003cp\u003eDays in hospital (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e62.54\u0026thinsp;\u0026plusmn;\u0026thinsp;11.37\u003c/p\u003e\n \u003cp\u003e22.72\u0026thinsp;\u0026plusmn;\u0026thinsp;3.33\u003c/p\u003e\n \u003cp\u003e3.79\u0026thinsp;\u0026plusmn;\u0026thinsp;1.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e63.146\u0026thinsp;\u0026plusmn;\u0026thinsp;10.48\u003c/p\u003e\n \u003cp\u003e23.20\u0026thinsp;\u0026plusmn;\u0026thinsp;3.06\u003c/p\u003e\n \u003cp\u003e3.64\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.470\u003c/p\u003e\n \u003cp\u003e0.051\u003c/p\u003e\n \u003cp\u003e0.175\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedical condition, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNO\u003c/p\u003e\n \u003cp\u003eHypertension\u003c/p\u003e\n \u003cp\u003eDiabetes mellitus\u003c/p\u003e\n \u003cp\u003eCardiovascular disease\u003c/p\u003e\n \u003cp\u003eHyperlipidemia\u003c/p\u003e\n \u003cp\u003eInflammatory Bowel Diseases\u003c/p\u003e\n \u003cp\u003ePrevious abdominal surgery\u003c/p\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003cp\u003eIndication for colonoscopy, n (%)\u003c/p\u003e\n \u003cp\u003eAbdominal pain\u003c/p\u003e\n \u003cp\u003eDiarrhea\u003c/p\u003e\n \u003cp\u003eConstipation\u003c/p\u003e\n \u003cp\u003eOccult blood in stool\u003c/p\u003e\n \u003cp\u003eAnemia\u003c/p\u003e\n \u003cp\u003ePhysical examination\u003c/p\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e144(43.6)\u003c/p\u003e\n \u003cp\u003e113(34.2)\u003c/p\u003e\n \u003cp\u003e54(16.4)\u003c/p\u003e\n \u003cp\u003e16(4.8)\u003c/p\u003e\n \u003cp\u003e41(12.4)\u003c/p\u003e\n \u003cp\u003e23(7.0)\u003c/p\u003e\n \u003cp\u003e103(31.2)\u003c/p\u003e\n \u003cp\u003e57(17.3)\u003c/p\u003e\n \u003cp\u003e85(25.8)\u003c/p\u003e\n \u003cp\u003e52(15.8)\u003c/p\u003e\n \u003cp\u003e14(4.2)\u003c/p\u003e\n \u003cp\u003e33(10)\u003c/p\u003e\n \u003cp\u003e9(2.7)\u003c/p\u003e\n \u003cp\u003e82(24.8)\u003c/p\u003e\n \u003cp\u003e55(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e164(47.8)\u003c/p\u003e\n \u003cp\u003e105(30.6)\u003c/p\u003e\n \u003cp\u003e42(12.2)\u003c/p\u003e\n \u003cp\u003e13(3.8)\u003c/p\u003e\n \u003cp\u003e33(9.6)\u003c/p\u003e\n \u003cp\u003e32(9.3)\u003c/p\u003e\n \u003cp\u003e89(25.9)\u003c/p\u003e\n \u003cp\u003e42(12.2)\u003c/p\u003e\n \u003cp\u003e79(23.0)\u003c/p\u003e\n \u003cp\u003e57(16.6)\u003c/p\u003e\n \u003cp\u003e21(6.1)\u003c/p\u003e\n \u003cp\u003e45(13.1)\u003c/p\u003e\n \u003cp\u003e6(1.7)\u003c/p\u003e\n \u003cp\u003e95(27.7)\u003c/p\u003e\n \u003cp\u003e42(12.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.277\u003c/p\u003e\n \u003cp\u003e0.314\u003c/p\u003e\n \u003cp\u003e0.127\u003c/p\u003e\n \u003cp\u003e0.499\u003c/p\u003e\n \u003cp\u003e0.245\u003c/p\u003e\n \u003cp\u003e0.264\u003c/p\u003e\n \u003cp\u003e0.131\u003c/p\u003e\n \u003cp\u003e0.660\u003c/p\u003e\n \u003cp\u003e0.410\u003c/p\u003e\n \u003cp\u003e0.762\u003c/p\u003e\n \u003cp\u003e0.272\u003c/p\u003e\n \u003cp\u003e0.206\u003c/p\u003e\n \u003cp\u003e0.390\u003c/p\u003e\n \u003cp\u003e0.401\u003c/p\u003e\n \u003cp\u003e0.103\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003ePEG, polyethylene glycol; CaO, castor oil\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eComparison of colonoscopy results\u003c/strong\u003e\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003eThe rates for adequate bowel preparation in the 4L-PEG and 2L-PEG-CaO groups were 72.4% and 77.3%, respectively, with no statistically significant difference between the two groups (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.148). In addition, the rates of polyp detection were 30.9% and 35.9%, adenoma detection were 13.0% and 14.9%, cancer detection were 2.7% and 4.1%, and colitis detection were 26.4% and 22.2%, respectively, between the two groups, with no statistically significant differences between the two groups(\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05) ( Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab2\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of colonoscopy results\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e4-PEG(n\u0026thinsp;=\u0026thinsp;330)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2-PEG-CaO(n\u0026thinsp;=\u0026thinsp;343)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAdequate bowel\u003c/p\u003e\n \u003cp\u003epreparation, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e239(72.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e265(77.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.148\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedical results, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNormal\u003c/p\u003e\n \u003cp\u003ePolyps\u003c/p\u003e\n \u003cp\u003eAdenoma\u003c/p\u003e\n \u003cp\u003eCancer\u003c/p\u003e\n \u003cp\u003eColitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e74(22.4)\u003c/p\u003e\n \u003cp\u003e102(30.9)\u003c/p\u003e\n \u003cp\u003e43(13.0)\u003c/p\u003e\n \u003cp\u003e9(2.7)\u003c/p\u003e\n \u003cp\u003e87(26.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e57(16.6)\u003c/p\u003e\n \u003cp\u003e123(35.9)\u003c/p\u003e\n \u003cp\u003e51(14.9)\u003c/p\u003e\n \u003cp\u003e14(2.1)\u003c/p\u003e\n \u003cp\u003e76(22.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.057\u003c/p\u003e\n \u003cp\u003e0.174\u003c/p\u003e\n \u003cp\u003e0.492\u003c/p\u003e\n \u003cp\u003e0.334\u003c/p\u003e\n \u003cp\u003e0.203\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e15(4.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22(6.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.288\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003ePEG, polyethylene glycol; CaO, castor oil\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eComparison of Boston Bowel Preparation Scores\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cp\u003eThere was no significant difference between the two groups in terms of scoring the quality of bowel preparation, with a mean (SD) total score of 6.79\u0026thinsp;\u0026plusmn;\u0026thinsp;1.51 for the 4L-PEG group and 7.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71 for 2L-PEG-Cao group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.056). The analysis of the segmental (right, transverse, and left colon) BBPS scale showed no difference for the right side (2.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79 vs 2.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71) and transverse colon (2.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68 vs 2.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68). However, the left colon score was significantly higher in the 2L-PEG-CaO group than in the 4L-PEG group (2.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68 vs 2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.038). Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e presents the results of bowel cleansing quality assessment based on the BBPS.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab3\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of Boston bowel preparation score between the two groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e4-PEG(n\u0026thinsp;=\u0026thinsp;330)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2-PEG-CaO(n\u0026thinsp;=\u0026thinsp;343)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRight side of colon (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.475\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMid colon (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.141\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLeft side of colon (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.038\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBBPS (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.79\u0026thinsp;\u0026plusmn;\u0026thinsp;1.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.056\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003ePEG, polyethylene glycol; CaO, castor oil\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eComparison of Patient\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eCompliance and Adverse Effects\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e shows the incidence of bowel preparation-related adverse events, including nausea/vomiting, abdominal pain, and bloating. There was a statistical difference between the two groups in terms of nausea/vomiting and abdominal distention (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The incidence of abdominal pain in the 2L-PEG-CaO group was higher than that in the 4L-PEG group. However, the difference was not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.324). The 2L-PEG-CaO group reported fewer overall adverse events than the 4L-PEG group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab4\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of adverse reactions between the two groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e4-PEG(n\u0026thinsp;=\u0026thinsp;330)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2-PEG-CaO(n\u0026thinsp;=\u0026thinsp;343)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNausea/Vomiting, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e62(18.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e19(5.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAbdominal pain, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e53(16.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e65(19.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.324\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBloating, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98(29.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e31(9.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTotal, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e213(64.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e115(33.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003ePEG, polyethylene glycol; CaO, castor oil, *\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eEarly screening for colon cancer is the most effective method to reduce the prevalence and mortality of colorectal cancer. Colonoscopy is an important tool for diagnosing and screening colon lesions, and ideal bowel preparation is an important step to complete the colonoscopy[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The ideal bowel preparation method not only needs to clean the bowel effectively, but also needs to be easily accepted by the patient[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt is well known that the inpatient status has been identified as a risk factor for inadequate bowel preparation[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Our study found that about 30% of patients had inadequate bowel preparation, which may affect the detection rate of colon polyps and neoplasms and increase the need for repeat testing[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Patients may also have increased hospital stay and costs as a result.\u003c/p\u003e \u003cp\u003eStudies have identified factors affecting bowel cleansing in inpatients[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. We cannot improve the quality of bowel preparation by changing in patient with complications such as diabetes or the length of hospital stay before colonoscopy. However, bowel cleansing can be improved by modifying the dosing regimen of bowel preparation and the type of bowel preparation. It is worth noting that the main method of high quality colonoscopy in the outpatient setting is by means of a split-dose approach[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], which is equally widely implemented in clinical practice in inpatients. It is generally accepted that \"hard-to-prepare\" patients need at least 4 liters of solution, and possibly more[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. However, a clinical study suggested that high-volume regimens are no better than low-volume regimens for patients at risk of poor bowel cleansing[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. According to the current study, low-volume PEG combined with bisacodyl is a more suitable option for patients with a history of colon resection[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Similarly, in patients with constipation, reinforced low volume PEG and high volume PEG have similar bowel cleansing effects[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. These findings are strongly correlated, in large part because low-volume bowel preparation increases patient tolerance and reduces the negative impact of the patient experience[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, we compared 2L PEG plus castor oil preparation with the standard-of-care 4L PEG preparation between bowel cleansing quality and inpatient tolerability, with the aim of finding a better bowel preparation method. The mechanism of castor oil to clean the intestinal tract is that after oral administration of castor oil, it is decomposed into ricinoleic acid in the duodenum, which stimulates the small intestine and promotes its peristalsis and excretion, thereby inducing a strong laxative effect[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Studies have found that after orally taken a large dose 50 or 60 ml of castor oil, the incidence of adverse reactions such as abdominal cramping, bloating, nausea, vomiting, syncope, and coma increases in patients[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. However, low doses of castor oil do not cause serious side effects and it has therefore become widely available as a safe stimulant laxative[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e], except for pregnant women[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. There is evidence that 30ml of castor oil reduces the amount of bowel preparation solution that can be prepared[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. In response, In order to increase the conductivity of castor oil in bowel preparation within safety limits, we designed a bowel preparation protocol of 2L PEG combined with 40ml castor oil. Our study found, according to the BBPS results, the quality of left colon cleansing using 2L PEG combined with castor oil was significantly higher than that of traditional 4L PEG regimen, but the quality of whole colon cleansing was similar. 2L PEG combined with castor oil for bowel preparation achieved the same cleanse results as the standard 4L PEG regimen. However, the 2L-PEG-CaO regimen was significantly lower than the 4L-PEG regimen in terms of the incidence of adverse events (e.g. nausea/vomiting, abdominal distension). In addition, the medical cost of the 2L-PEG-CaO regimen was also lower than that of the 4L-PEG regimen. Therefore, the 2L-PEG-CaO regimen greatly increases patient satisfaction and compliance. From our research results, the incidence of abdominal pain in the 2L-PEG-CaO regimen is higher than that in the 4L-PEG regimen. In this regard, we consider that the moderate dose of castor oil is related to the increase in intestinal peristalsis. Although there was no significant difference in the incidence of abdominal pain between the two groups, we still need to pay attention to the patient's experience, and in future studies, we need to consider whether 2L PEG combined with different doses of castor oil can have similar or more effective bowel cleansing to reduce the incidence of abdominal pain in patients.\u003c/p\u003e"},{"header":"Limitations","content":"\u003cp\u003eWe have to confess some limitations to our study. First, this is a retrospective study, and the clinical information of the patients is extracted from the medical record system, so the obtained information is prone to bias. In this regard, in the future, our team will conduct randomized controlled clinical trials in the future to verify the conclusions of this study. However, there is an advantage to this study, as the inpatients in this study underwent bowel preparation under full medical supervision, reducing confounding factors associated with poor bowel preparation, such as type of diet before colonoscopy, bowel preparation the experience of preparing and the time to start preparing. However, this study has the advantage in that, in order to reduce the confounding factors related to poor bowel preparation, such as type of diet before colonoscopy, the experience or knowledge of bowel preparation, and the time to start preparation, the hospitalized patients of this study under the supervised of the entire course of medical care were bowel preparation. Second, while BBBS scores are validated and widely used to evaluate bowel cleansing effects, there is a subjective judgment between each endoscopist, which may indicate a bias in the evaluation of the two methods of intestinal preparation. Third, despite our large sample size, this study is still a single-center study, so a larger study is needed to validate and generalize our conclusions. Fourth, adenoma detection rate (ADR), polyp detection rate, and colon tumor detection rate are important quality control indicators for colonoscopy screening, which were not found in the cases investigated in this study.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, the results of this study suggest that it is safe for hospitalized patients to use 2L PEG combined with 40 ml CaO for bowel preparation before colonoscopy, it obtains the same quality of bowel preparation to traditional 4L split PEG, and it improves patient satisfaction and compliance with bowel preparation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective study was in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Affiliated Changzhou No.2 People\u0026rsquo;s Hospital of Nanjing Medical University. The patients provided their written informed consent to participate in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of funding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Changzhou Second People\u0026apos;s Hospital Fund (2019HZD001) and the Nanjing Medical University Fund (NMUC2021026A). The funders had no role in study design, data collection and analysis, publication decisions or manuscript preparation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of financial/other relationships\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors claim no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eZX drafted the manuscript. JH provided design ideas for this study, and YF, FFF, YMC, HHZ, CYH participated in data analysis and supplemented ideas. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors consent to publish.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSchreuders EH, Ruco A, Rabeneck L, Schoen RE, Sung JJ, Young GP, Kuipers EJ: \u003cb\u003eColorectal cancer screening: a global overview of existing programmes\u003c/b\u003e. Gut 2015, \u003cb\u003e64\u003c/b\u003e(10):1637\u0026ndash;1649.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZauber AG, Winawer SJ, O'Brien MJ, Lansdorp-Vogelaar I, van Ballegooijen M, Hankey BF, Shi W, Bond JH, Schapiro M, Panish JF \u003cem\u003eet al\u003c/em\u003e: \u003cb\u003eColonoscopic polypectomy and long-term prevention of colorectal-cancer deaths\u003c/b\u003e. 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Turk J Surg 2018, \u003cb\u003e34\u003c/b\u003e(1):28\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eT\u0026eacute;llez-\u0026Aacute;vila FI, Murcio-P\u0026eacute;rez E, Sa\u0026uacute;l A, Herrera-G\u0026oacute;mez S, Valdovinos-Andraca F, Acosta-Nava V, Barreto R, Elizondo-Rivera J: \u003cb\u003eEfficacy and tolerability of low-volume (2 L) versus single- (4 L) versus split-dose (2 L + 2 L) polyethylene glycol bowel preparation for colonoscopy: randomized clinical trial\u003c/b\u003e. Dig Endosc 2014, \u003cb\u003e26\u003c/b\u003e(6):731\u0026ndash;736.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahmood S, Farooqui SM, Madhoun MF: \u003cb\u003ePredictors of inadequate bowel preparation for colonoscopy: a systematic review and meta-analysis\u003c/b\u003e. Eur J Gastroenterol Hepatol 2018, \u003cb\u003e30\u003c/b\u003e(8):819\u0026ndash;826.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFrazzoni L, Radaelli F, Spada C, Mussetto A, Frazzoni M, Laterza L, Rondonotti E, La Marca M, Zagari RM, Piccirelli S \u003cem\u003eet al\u003c/em\u003e: \u003cb\u003eThe diagnostic yield of colonoscopy in hospitalized patients. An observational multicenter prospective study\u003c/b\u003e. Dig Liver Dis 2021, \u003cb\u003e53\u003c/b\u003e(2):224\u0026ndash;230.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRex DK: \u003cb\u003eBowel preparation for colonoscopy: entering an era of increased expectations for efficacy\u003c/b\u003e. 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J Gastroenterol Hepatol 1999, \u003cb\u003e14\u003c/b\u003e(12):1219\u0026ndash;1222.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBradley AJ, Taylor PM: \u003cb\u003eDoes bowel preparation improve the quality of intravenous urography?\u003c/b\u003e Br J Radiol 1996, \u003cb\u003e69\u003c/b\u003e(826):906\u0026ndash;909.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJansson M, Geijer H, Andersson T: \u003cb\u003eBowel preparation for excretory urography is not necessary: a randomized trial\u003c/b\u003e. Br J Radiol 2007, \u003cb\u003e80\u003c/b\u003e(956):617\u0026ndash;624.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSicuranza GB, Figueroa R: \u003cb\u003eUterine rupture associated with castor oil ingestion\u003c/b\u003e. J Matern Fetal Neonatal Med 2003, \u003cb\u003e13\u003c/b\u003e(2):133\u0026ndash;134.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTian X, Shi B, Liu XL, Chen H, Chen WQ: \u003cb\u003eA Randomized Trial of Split Dose 3 L Polyethylene Glycol Lavage Solution, 2 L Polyethylene Glycol Lavage Combined With Castor Oil, and 1 L of Polyethylene Glycol Lavage Solution Combined With Castor Oil and Ascorbic Acid for Preparation for Colonoscopy\u003c/b\u003e. Front Med (Lausanne) 2019, \u003cb\u003e6\u003c/b\u003e:158.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"castor oil, bowel preparation, polyethylene glycol, colonoscopy, inpatients","lastPublishedDoi":"10.21203/rs.3.rs-1852987/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1852987/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjectives\u003c/strong\u003e: The study aimed to compare the cleansing effect, compliance and adverse of polyethylene glycol 2L with castor oil and polyethylene glycol 4L on bowel preparation prior to colonoscopy in inpatients.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: Our study retrospectively analyzed the medical records and colonoscopy reports of inpatients (n=673) who underwent colonoscopy at the Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University, and the inpatients were divided into two groups according to different bowel preparation protocols. BBPS is used to assess the degree of bowel cleanliness before colonoscopy. We statistically analyzed and compared the degree of bowel cleansing between 2L-PEG-CaO and 4L-PEG group, as well as the compliance and adverse effects of the medication in both groups.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: Among 673 patients undergoing colonoscopy, 330 were prescribed 4L-PEG and 343 2L-PEG-CAO. Both groups of inpatients were matched for baseline characteristics. In the 4L-PEG and 2L-PEG-CaO groups, adequate bowel preparation rate was 72.4% and 77.3% (\u003cem\u003eP\u003c/em\u003e=0.148), BBPS scores was 6.79±1.51 and 7.03±1.71 (\u003cem\u003eP\u003c/em\u003e=0.056), and adverse event rate was 68.2% and 30.0% (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001), respectively.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: The 2L-PEG combined with castor oil is an effective and safe cleansing regimen for bowel preparation and is relatively inexpensive and suitable for wider use. \u003c/p\u003e","manuscriptTitle":"2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-07-26 19:40:21","doi":"10.21203/rs.3.rs-1852987/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"307fb3da-8abe-4669-84f9-68b1394b8135","owner":[],"postedDate":"July 26th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-09-19T06:14:33+00:00","versionOfRecord":[],"versionCreatedAt":"2022-07-26 19:40:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1852987","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1852987","identity":"rs-1852987","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}