Bowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study

Bowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study | 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 Study protocol Bowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study Roberto Ulises Cruz Neri, Jesús Alonso Valenzuela Pérez, Francisco Javier Valadez Correa, and 14 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8282068/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 Background Adequate bowel preparation is essential to ensure optimal visualization during colonoscopy, directly influencing lesion detection rates, procedural success, and overall diagnostic performance. Although Polyethylene Glycol (PEG) is widely used as the standard preparation, Lactulose has emerged as a potential alternative due to its tolerability and availability. Evidence comparing their effectiveness has shown mixed results, and further evaluation is warranted. This multicenter, randomized, double-blind clinical trial aimed to compare Lactulose and Polyethylene Glycol in terms of bowel cleansing quality, endoscopic performance, and diagnostic yield. Methods Of 606 enrolled patients, 449 met inclusion criteria and were randomized to receive either Lactulose (n = 178) or Polyethylene Glycol (n = 271). Colonoscopies were performed at two tertiary hospitals. Demographic variables, comorbidities, and indications for colonoscopy were recorded. Statistical analysis was conducted using IBM SPSS v25. Quantitative variables were compared using the Student’s t test for independent samples, with assumptions of normality (Kolmogorov–Smirnov) and homogeneity of variances (F-test) verified. Categorical variables were analyzed with chi-square testing. The Boston Bowel Preparation Scale (BBPS) was used to assess bowel cleanliness in each colon segment and overall. Endoscopic outcomes (including cecal intubation rate, cecal intubation time, and macroscopic mucosal changes) were compared. Diagnostic yield was evaluated through the Adenoma Detection Rate (ADR). Results Both groups were statistically comparable at baseline in terms of age, sex, and comorbid conditions. Only the indication of lower gastrointestinal bleeding differed significantly, occurring more frequently in the PEG group; however, this imbalance did not influence key outcomes. Macroscopic mucosal changes such as edema, hyperemia, or bleeding were infrequent and showed no significant association with the type of preparation (3.24% vs. 5.13%; p = 0.364). Across colon segments (including ascending, transverse, and descending) the BBPS scores were nearly identical, with no statistical differences observed. The total BBPS score also showed comparable results (Lactulose: 7.21 ± 1.61 vs. PEG: 7.08 ± 1.49; p = 0.37; 95% CI –0.42 to 0.162), demonstrating equivalent cleansing efficacy.Endoscopic performance indicators were similarly consistent between groups. Cecal intubation rates were 94.4% for Lactulose and 94.1% for PEG (p = 0.85), aligning closely with international standards. Cecal intubation time showed no statistical difference. Diagnostic yield, assessed through ADR, revealed a nonsignificant trend toward higher detection in the PEG group (26.4% vs. 32.1%; p = 0.236). Overall, neither preparation demonstrated superiority in adenoma detection. Conclusion This randomized, double-blind, multicenter clinical trial demonstrates that Lactulose and Polyethylene Glycol offer equivalent efficacy as bowel preparations for colonoscopy. Both agents resulted in comparable cleansing quality across all colon segments, similar cecal intubation rates and times, and no significant differences in adenoma detection. These findings support the use of Lactulose as a clinically valid alternative to PEG, allowing for flexibility in preparation choice based on patient tolerance, cost considerations, availability, and institutional preferences—without compromising procedural quality or diagnostic performance. Bowel preparation Colonoscopy Lactulose Polyethylene Glycol Boston Bowel Preparation Scale Cecal intubation rate Adenoma Detection Rate Figures Figure 1 Background Colonoscopy is the gold standard for the detection, diagnosis, and prevention of colorectal cancer, as it allows complete visualization of the colonic mucosa, identification and removal of premalignant lesions, and diagnosis of early-stage neoplasia. 1 Its diagnostic and therapeutic effectiveness, however, depends fundamentally on the quality of bowel preparation. 2 Suboptimal cleansing impairs visualization, decreases adenoma detection rates (ADR), prolongs procedure time, increases healthcare costs, and is associated with a higher risk of post-colonoscopy colorectal cancer (PCCRC). 3 Moreover, inadequate preparation frequently requires repeating the procedure and results in a less satisfactory patient experience. 4 Achieving adequate bowel cleansing requires not only selecting an effective preparation regimen but also ensuring proper patient education, adherence to dietary restrictions, and optimizing the timing of the last dose. 5 Current evidence indicates that the interval between the final dose of the preparation and the start of colonoscopy plays a pivotal role in cleansing quality. 6 The European Society of Gastrointestinal Endoscopy recommends an interval of no more than four hours, while expert consensus suggests an optimal window of 3–8 hours, regardless of the specific preparation used. 7 Likewise, low-residue diets are generally better tolerated than clear-liquid diets and may contribute to improved cleansing efficacy, although evidence remains insufficient to recommend one specific diet or duration. 8 Bowel preparations are frequently categorized as osmotic or polyethylene glycol (PEG)-based solutions. 9,10 PEG regimens are widely used and considered the standard preparation due to their safety, non-absorbable nature, and metabolic neutrality. 11 Osmotic alternatives (including sodium phosphate, magnesium citrate, mannitol, and lactulose) act by increasing water retention or stimulating secretion in the colon. 12 Among these, Lactulose has gained attention for its tolerability, palatability, and accessibility, positioning it as a potential alternative to PEG. 13 Nevertheless, studies comparing PEG and lactulose have produced mixed findings, with variability in reported efficacy, adverse effects, and patient satisfaction. 14 To standardize the assessment of bowel cleansing, guidelines recommend the use of validated scoring systems such as the Aronchick Bowel Preparation Scale (ABPS), the Ottawa Bowel Preparation Scale (OBPS), the Boston Bowel Preparation Scale (BBPS), and the Harefield scale. 15 Each offers specific advantages and limitations, and their systematic use strengthens quality monitoring and reporting. 16 Despite the availability of effective regimens and validated scales, up to 20–25% of patients still present with inadequate preparation, underscoring the influence of modifiable risk factors such as dietary adherence, dosing regimen, comorbidities, concomitant medications, hospitalization, and advanced age. 17 Inadequate bowel preparation also adversely impacts key quality indicators, including ADR, cecal intubation rate, and withdrawal time. 18 Since ADR is recognized globally as the most important colonoscopy quality indicator (given its strong association with reductions in PCCRC incidence, advanced PCCRC, and PCCRC-related mortality) improving bowel preparation remains a clinical priority. 19 Furthermore, suboptimal cleansing increases the likelihood of missed flat or serrated lesions, shortens surveillance intervals, prolongs hospital stays, and may render screening colonoscopy less cost-effective. 20 Given the persistent rates of inadequate preparation and the need to optimize patient tolerability and adherence, further comparative evaluation of available bowel preparations is warranted. 21 In this context, polyethylene glycol and lactulose represent two commonly used but mechanistically distinct alternatives. 22 Comparing their impact on cleansing quality, endoscopic performance, tolerability, adverse effects, and patient experience is essential to guide clinical decision-making and improve the effectiveness of colonoscopy as both a diagnostic and preventive tool. 23 , 24 Materials and methods Main objective To compare bowel preparation with Lactulose versus Polyethylene Glycol as the optimal agent for performing high-quality colonoscopies at the Hospital Civil Fray Antonio Alcalde and Hospital Civil Juan I. Menchaca, during the period from July 1, 2024, to July 31, 2025. Design This was a randomized, multicenter, double-blind clinical trial conducted in the colorectal surgery departments of the Hospital Civil Fray Antonio Alcalde and Hospital Civil Juan I. Menchaca (Guadalajara, Mexico) between August 2024 and July 2025. A total of 449 patients met the inclusion criteria, aged ≥ 18 years, with a valid indication for scheduled colonoscopy, and capable of providing informed consent. Participants were randomly assigned to one of two bowel preparation groups: Lactulax® (Lactulose): 178 patients and Nulytely® (Polyethylene Glycol, PEG): 271 patients Exclusion criteria included a history of intestinal obstruction, known intolerance to lactulose or PEG, pregnancy or breastfeeding, and comorbidities potentially interfering with study participation. Additional elimination criteria were voluntary withdrawal, inability to complete colonoscopy, or significant intolerance to the assigned preparation. Procedure Following randomization, patients received instructions regarding dietary restrictions and the preparation regimen according to their assigned group. Tolerability, gastrointestinal adverse events, and adherence were monitored during the preparation. Colonoscopy was subsequently performed using standard techniques, and bowel cleansing quality was assessed with the Boston Bowel Preparation Scale (BBPS). Quantitative variables (age, coagulation time, withdrawal time) were compared using the Student’s t-test for independent samples, after assessing normality (Kolmogorov-Smirnov) and homogeneity of variances (F-test). Categorical variables (sex, comorbidities, cecal intubation) were analyzed using the chi-square test. A baseline description of both groups was also performed in terms of age, sex, and comorbidities. Statistical Analysis The validated dataset was imported into IBM SPSS v25 for statistical analysis. Descriptive statistics were used to summarize the characteristics of the study population. Quantitative variables, including age, coagulation time, and withdrawal time, were compared between groups using the Student’s t-test for independent samples, after assessing normality (Kolmogorov-Smirnov) and homogeneity of variances (F-test). Categorical variables, such as sex, comorbidities, and cecal cannulation, were analyzed using the chi-square test to evaluate independence between groups. Statistical significance was set at p < 0.05, and the analyses provided a basis for drawing evidence-based conclusions. Results A total of 606 patients were included, of whom 449 met the inclusion criteria and underwent colonoscopy in the colorectal surgery services of two different hospital units: the Old Civil Hospital of Guadalajara “Fray Antonio Alcalde” and the Civil Hospital “Juan I. Menchaca,” in Guadalajara, Jalisco, Mexico. All patients signed an informed consent form. Subsequently, a randomization process was carried out, assigning participants to two different bowel preparation groups: Lactulax® (Lactulose): 178 patients, and Nulytely® (Polyethylene Glycol): 271 patients (Figure 1) The analysis was performed using IBM SPSS v25. To compare quantitative variables (age, coagulation time, withdrawal time) between both groups, the Student’s t-test for independent samples was used. Assumptions of normality (Kolmogorov-Smirnov) and homogeneity of variances (F-test) were evaluated. Categorical variables (sex, comorbidities, cannulation) were analyzed using the chi-square test to assess independence between groups. A baseline description of the groups was conducted in terms of age, sex, and comorbidities (Table 1). Both age and sex showed a similar distribution between patients prepared with Lactulose and those prepared with Polyethylene Glycol. No statistically significant differences were identified in either of these parameters, supporting that both groups are comparable in terms of baseline demographic characteristics and were balanced with respect to these variables. The two groups were clinically similar in all comorbidities and study indications, except for LGIB (lower gastrointestinal bleeding), which was significantly more frequent in the group that received Polyethylene Glycol bowel preparation. However, this factor does not influence the results related to the Boston score or adenoma detection, and therefore, we consider it does not have relevant weight in this study. Table 1. Demographic characteristics, comorbidities, and study indications in bowel preparation using Lactulose vs. Polyethylene Glycol. Variable Lactulose (N: 178) Polyethylene glycol (N:271) P-value Age 57.65 (± 13.10) 55.62 (± 14.29) 0.122 Male sex 69 (38.8%) 107 (39.5%) 0.921 Female sex 109 (61.2%) 164 (60.5%) Comorbidity Diabetes Mellitus 40 (22.5%) 50 (18.5%) 0.335 Hypertension 44 (24.7%) 76 (28%) 0.448 Human immunodeficiency virus 7 (3.9%) 4 (1.5%) 0.123 Any type of cancer 4 (2.2%) 4 (1.5%) 0.718 Study indication LGIB 63 (35.4%) 135 (49.8%) 0.003 CRC screening 142 (79.8%) 214 (79%) 0.905 IBD 2 (1.1%) 8 (2.9%) 0.327 Diverticula 11 (6.18%) 14 (5.1%) 0.677 In the comparison of the macroscopic changes observed during the procedure—specifically edema, hyperemia, or bleeding—a frequency of 3.24% was identified in the group that received lactulose and 5.13% in the group that used polyethylene glycol (Table 2). However, no statistically relevant association was found (p = 0.364). These results indicate that the presence of macroscopic alterations was low in both groups and comparable between them, with no evidence that the type of bowel preparation influences the occurrence of these changes. Table 2. Macroscopic changes during the procedure following bowel preparation with Lactulose vs. Polyethylene Glycol. Macroscopic changes Lactulose (N:185) Polyethylene glycol (N:273) P-value Edema, hyperemia, bleeding 6 (3.24%) 14 (5.13%) 0.364 Similarly, the effect on the ascending colon, transverse colon, and the total Boston score (Table 3), as well as on the descending colon (Table 4), and the overall score (Table 5, Grafic 1) was evaluated. These were analyzed separately due to the differences in the number of observations obtained in each of them. Table 3. Results of the comparison of the Boston Bowel Preparation Scale scores in the ascending and transverse colon segments using Lactulose vs. Polyethylene Glycol. Segment Lactulose (N:174) Polyethylene glycol (N:263) P-value Mean SD Ascending colon 2.43 ± 0.648 0.98 2.43 ± 0.581 Transverse colon 2.45 ± 0.668 0.27 2.39 ± 0.540 Table 4. Results of the comparison of the Boston score in the descending colon segment using Lactulose vs. Polyethylene Glycol. Segment Lactulose (N:174) Polyethylene glycol (N:260) P-value Mean SD Descending colon 2.39 ± .615 0.98 2.39 ± .660 Table 5. Results of the comparison of the total Boston score using Lactulose vs. Polyethylene Glycol for bowel preparation. Total Boston Score Lactulose (N:175) Polyethylene Glycol (N:267) P-value IC 95% Mean SD 7.21 ± 1.61 0.37 -0.42 – 0.162 7.08 ± 1.49 Graphic 1: Comparación of Bowel Preparation Scores (Lactulose vs. Polyethylene Glycol) With regard to colonoscopy, the rate of successful intubation of the ileocecal valve was compared between both groups. In the Lactulose group, the success rate was 168 (94.4%), and in the Polyethylene Glycol group it was 255 (94.1%), with a p-value of 0.85. Likewise, the mean cecal intubation time showed no statistically significant differences. (Table 7). Cecum reached: 423 / 449 = 94.25% International standard: >95% Table 6. Comparison of cecal intubation time using Lactulose vs. Polyethylene Glycol bowel preparation. Cecal intubation time (seconds) Lactulose (N: 178) Polyethylene glycol (N:271) P-value IC 95% 658.16 ( ± 422.39 ) s 694.63 (± 453.8) s 0.85 -47.26 – 120.2 The overall cannulation rate (94.25%) was slightly below the international standard (>95%), although still close to the optimal level. No significant differences were found between the preparations in terms of success rate or cecal intubation times. Regarding the effect of the type of bowel preparation on the total number of polyps identified (Adenoma Detection Rate: ADR), whose mean values and statistics are shown below (Table 7), although the Polyethylene Glycol group showed a higher proportion of detected polyps, this difference did not reach statistical significance (p = 0.236). It cannot be concluded that either preparation improves the ADR in this study. Table 7. Adenoma Detection Rate (ADR): Positive polyp detection using Lactulose vs. Polyethylene Glycol bowel preparation. Bowel preparation Adenoma P-value Lactulose (N:178) 47 (26.4%) 0.236 Polyethylene glycol (N: 271) 87 (32.1%) Discussion In this study, two bowel preparation regimens, Lactulose and Polyethylene Glycol (PEG), were compared with the aim of determining whether significant differences existed in the quality of colonic cleansing, endoscopic parameters, and diagnostic yield, using a non-inferiority approach. The available literature has previously explored this comparison; for example, the clinical trial by Aliaga Ramos et al. 25 reported superiority of lactulose preparation, achieving higher polyp detection rates compared with PEG. These findings have generated interest regarding the potential diagnostic benefit of lactulose as an alternative to conventional PEG-based preparations. 26 In line with this line of research, the randomized study published by Rashid et al. 27 directly compared lactulose with PEG in 40 patients and also found no significant differences in the quality of bowel preparation as measured by the Boston score. The authors reported similar values between groups (6.25 ± 0.786 vs. 6.35 ± 0.813; p = 0.59), concluding that both options are equally effective in achieving adequate colon cleansing. In our analysis, the groups showed homogeneity in their demographic and clinical characteristics, which helps minimize bias and increases the certainty that the results can be attributed to the type of preparation used. The absence of differences in age, sex, and comorbidities indicates an adequate allocation process and balanced comparison between the groups. Regarding the quality of bowel cleansing, no significant differences were found in the Boston Bowel Preparation Scale, either in individual segments or in the total score, suggesting equivalent efficacy between lactulose and PEG. This result is consistent with previous reports by both Aliaga Ramos 25 and Rashid et al. 27 , reinforcing the idea that lactulose is a valid alternative with outcomes comparable to PEG for optimizing endoscopic visualization. Similarly, cecal intubation showed equivalent rates between groups, with no significant differences in the technical success of the procedure or the time required. Although the overall intubation rate (94.25%) was slightly below the international standard (> 95%), it remained within the acceptable range, indicating that the choice of preparation did not affect endoscopic performance. With respect to diagnostic yield, no significant differences were observed in the ADR (Adenoma Detection Rate). Although the PEG group showed a slightly higher proportion of polyp detection, the lack of statistical significance suggests that this difference could be due to chance. This finding is consistent with the results of the study by Rashid et al. 27 , which also reported no differences in the detection of neoplastic lesions between lactulose and PEG. The only parameter that showed a significant difference was the indication for the procedure due to rectal bleeding, which was more frequent in the PEG group. However, this finding was not related to variations in the main outcomes and did not impact the quality of preparation or lesion detection; therefore, its clinical relevance is limited. Overall, the results of the present study confirm that lactulose and polyethylene glycol are clinically equivalent options for bowel preparation prior to colonoscopy. Both demonstrated similar efficacy, tolerability, and diagnostic performance. These findings support the individualized selection of bowel preparation based on availability, patient tolerance, cost, and institutional resources, without compromising the quality or diagnostic utility of the procedure. 28 Conclusion The results of this study demonstrate that bowel preparation with Lactulose and Polyethylene Glycol provides equivalent performance across all evaluated parameters. The quality of bowel cleansing, measured using the Boston Bowel Preparation Scale, was similar in both groups, with no significant differences in any colon segment or in the total score. Likewise, endoscopic performance, including cecal intubation rate and intubation time, showed no differences between the two preparations, indicating that the choice of bowel preparation does not influence the technical ease of the procedure. Similarly, polyp detection and ADR were comparable, suggesting that neither preparation confers a diagnostic advantage over the other. Altogether, these findings support the conclusion that both preparations are clinically equivalent and can be used interchangeably in clinical practice, with the final choice depending on availability, patient tolerance, cost, and institutional criteria, without compromising procedure quality or diagnostic yield. Abbreviations HCFAA Hospital Civil Fray Antonio Alcalde HCJIM Hospital Civil Juan I. Menchaca PEG Polyethylene Glycol BBPS Boston Bowel Preparation Scale ADR Adenoma Detection Rate LGIB Lower Gastrointestinal Bleeding CRC Colorectal Cancer IBD Inflammatory Bowel Disease. Declarations Acknowledgements The authors would like to express their gratitude to the Hospital Civil “Fray Antonio Alcalde” and the Hospital Civil “Juan I. Menchaca” for their support in the development of this study. We extend our appreciation to Dr. Roberto Ulises Cruz Neri, Head of the Coloproctology Service at Hospital Civil “Fray Antonio Alcalde” and principal investigator of the project, and to Dr. Jesús Alonso Valenzuela Pérez, Head of the Coloproctology Service at Hospital Civil “Juan I. Menchaca,” for their invaluable guidance and collaboration. Authors’ contributions C.N.R.U. served as Head of the Coloproctology Service at one of the participating hospitals, acted as principal investigator, led the project, and coordinated the recruitment of the research team. V.P.J.A. served as principal investigator at the second participating hospital and contributed to the overall supervision of the study. Z.M.L. provided essential data and contributions derived from her thesis work. V.C.F.J., G.D.J.A., H.G.F., S.N.M.M., G.G.J.C., V.I.C., and L.I.M.L. contributed to the study design, identification and Inclusion of eligible participants, and critical revision of the manuscript for important intellectual content. B.F.A., R.M.L.A., D.B.S.M., D.P.A.A., G.L.E.G., P.L.B., and B.A.M. participated in protocol development, clinical data collection, statistical analysis, and manuscript editing. All authors reviewed and approved the final version of the manuscript for publication. Funding This study did not receive financial support from any public, commercial, or non-profit funding agency. Data Availability The datasets generated and analyzed during the current study were recorded on standardized data collection sheets and subsequently stored in a secure, project-specific electronic database. Due to the presence of confidential patient information, full access to the dataset is restricted to the responsible investigators. De-identified data may be made available from the corresponding author upon reasonable request. Ethical approval and participant consent This study received approval from the Ethics and Research Committees of the Hospital Civil Fray Antonio Alcalde on April 25, 2025, under the Institutional Protocol Identifier 131/25. The protocol was also submitted and registered at ClinicalTrials.gov (Registration No. NCT06666556). Written informed consent was obtained from all participants prior to undergoing colonoscopy, with clear explanation of the study objectives, potential risks, and anticipated benefits. The investigation was conducted in accordance with the Mexican General Health Law pertaining to health research, as well as the ethical principles outlined in the Declaration of Helsinki (2013) and the Nuremberg Code (1947). Consent for publication Not applicable. Competing Interest The authors declare that they have no competing interests. Supported by This study was conducted without financial assistance from any public or private institution. Author details 1 Hospital Civil “Fray Antonio Alcalde” Coronel Calderón 777, El Retiro, 44200 City Guadalajara, State Jalisco, Country México. 2 Hospital Civil “Juan I. Menchaca” Salvador Quevedo y Zubieta 750, Independencia Oriente, 44340 City Guadalajara, State Jalisco, Country México. References Kim SY, Kim HS, Park HJ. Adverse events related to colonoscopy: Global trends and future challenges. World J Gastroenterol. 2019;25(2):190-204. doi:10.3748/wjg.v25.i2.190 Sullivan JF, Dumot JA. Maximizing the Effectiveness of Colonoscopy in the Prevention of Colorectal Cancer. Surg Oncol Clin N Am. 2018;27(2):367-376. doi:10.1016/j.soc.2017.11.009 Tamai N, Adachi S, Sumiyama K. Bowel preparation for improving the quality of colonoscopy. Digestive Endoscopy. 2022;34(6):1134-1135. doi:10.1111/den.14339 Seward E. Recent advances in colonoscopy. F1000Res. 2019;8. doi:10.12688/f1000research.18503.1 Parra-Blanco A, Ruiz A, Alvarez-Lobos M, et al. Achieving the best bowel preparation for colonoscopy. World J Gastroenterol. 2014;20(47):17709-17726. doi:10.3748/wjg.v20.i47.17709 Li CX, Guo Y, Zhu YJ, et al. Comparison of polyethylene glycol versus lactulose oral solution for bowel preparation prior to colonoscopy. Gastroenterol Res Pract. 2019;2019. doi:10.1155/2019/2651450 Hassan C, East J, Radaelli F, et al. Bowel preparation for colonoscopy: European society of gastrointestinal endoscopy (esge) guideline-update 2019. Endoscopy. 2019;51(8):775-794. doi:10.1055/a-0959-0505 Shahini E, Sinagra E, Vitello A, et al. Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature. World J Gastroenterol. 2023;29(11):1685-1707. doi:10.3748/wjg.v29.i11.1685 Wallace SK, Bakkum-Gamez JN. Bowel Preparation. The ERAS® Society Handbook for Obstetrics & Gynecology. Published online April 17, 2023:31-39. doi:10.1016/B978-0-323-91208-2.00007-X Wenqi S, Bei Z, Yunrong W, et al. Lactulose vs Polyethylene Glycol for Bowel Preparation: A Single-Center, Prospective, Randomized Controlled Study Based on BMI. Clin Transl Gastroenterol. 2024;15(1):e00652. doi:10.14309/ctg.0000000000000652 Zhang X, Chen Y, Chen Y, et al. Polyethylene glycol combined with lactulose has better efficacy than polyethylene glycol alone in bowel preparation before colonoscopy: A meta-analysis. Clinics (Sao Paulo). 2023;78:100172. doi:10.1016/j.clinsp.2023.100172 Di Leo M, Iannone A, Arena M, et al. Novel frontiers of agents for bowel cleansing for colonoscopy. World J Gastroenterol. 2021;27(45):7748-7770. doi:10.3748/wjg.v27.i45.7748 Xiong Z, Fang Y, Feng F, Cheng Y, Huo C, Huang J. 2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients. Medicine (United States). 2023;102(29):E34294. doi:10.1097/MD.0000000000034294 MENACHO AM, REIMANN A, HIRATA LM, GANZERELLA C, IVANO FH, SUGISAWA R. Double-blind prospective randomized study comparing polyethylene glycol to lactulose for bowel preparation in colonoscopy. ABCD Arquivos Brasileiros de Cirurgia Digestiva (São Paulo). 2014;27(1):9-12. doi:10.1590/s0102- 67202014000100003 Millien VO, Mansour NM. Bowel Preparation for Colonoscopy in 2020: A Look at the Past, Present, and Future. Curr Gastroenterol Rep. 2020;22(6). doi:10.1007/s11894-020-00764-4 Quintero E, Alarcón-Fernández O, Jover R. Controles de calidad de la colonoscopia como requisito de las campañas de cribado del cáncer colorrectal. Gastroenterol Hepatol. el 1 de noviembre de 2013;36(9):597–605. Endoscopia del intestino grueso (rectoscopia, rectosigmoidoscopia, colonoscopia) [Internet]. [citado el 9 de julio de 2024]. Disponible en: https://empendium.com/manualmibe/compendio/social/chapter/B34.V.26.2.3. Ramírez-Quesada W, Vargas-Madrigal J, Alfaro-Murillo O, Umaña-Solís E, Campos-Goussen C, Alvarado-Salazar M, et al. Indicadores de calidad para la realización de colonoscopia. Acta Médica Costarric. marzo de 2019;61(1):37–42. Hong SM, Baek DH. A Review of Colonoscopy in Intestinal Diseases. Diagnostics. el 27 de marzo de 2023;13(7):1262. Shahini E, Sinagra E, Vitello A et al. Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature. World J Gastroenterol. 2023;29(11):1685-1707. doi:10.3748/wjg.v29.i11.1685 Sánchez-del-Río A, Pérez-Romero S, López-Picazo J, Alberca-de-las-Parras F, Júdez J, León-Molina J, et al. Indicadores de calidad en colonoscopia. Procedimiento de la colonoscopia. Rev Esp Enfermedades Dig. 2018;110(5):316–26. Yadav J, Sawant G, Lal P, Bains L. Oral Lactulose vs. Polyethylene Glycol for Bowel Preparation in Colonoscopy: A Randomized Controlled Study. Cureus. Published online April 8, 2021. doi:10.7759/cureus.14363 Parekh PJ, Oldfield EC, Johnson DA. Bowel preparation for colonoscopy: What is best and necessary for quality? Curr Opin Gastroenterol. 2019;35(1):51-57. doi:10.1097/MOG.0000000000000494 Jagdeep J, Sawant G, Lal P, Bains L. Oral Lactulose vs. Polyethylene Glycol for Bowel Preparation in Colonoscopy: A Randomized Controlled Study. Cureus. 2021;13(4):e14363. doi:10.7759/cureus.14363 Shahini E, Sinagra E, Vitello A et al. Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature. World J Gastroenterol. 2023;29(11):1685-1707. doi:10.3748/wjg.v29.i11.1685 SHI W, ZHANG J, LIU P. Effectiveness of Lactulose for Colonoscopy Preparation in Adults:A Meta-Analysis. Medical Research. 2023;5(1). doi:10.6913/mrhk.050104 Aliaga Ramos J., et al. Comparación de lactulosa vs polietilenglicol en la preparación intestinal para colonoscopia. Ensayo clínico aleatorizado. Rashid A., et al. Oral Lactulose vs. Polyethylene Glycol for Bowel Preparation in Colonoscopy: A Randomized Controlled Study. Cureus. 2021;13(5):e14841. Graph Graph 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. 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Neri","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+klEQVRIiWNgGAWjYFACHhSehByIPPCAoJYEhBZjsJYE7GqxamFIbGBAFcAA5u29Bx9X/rCRN5+R/uzBxz0W6fPDDj8E2mInp9uAXYvMmXPJhmcS0gzn3EhIN5zxTCJ34+00A6CWZGOzA9i1SEjkmEk2JBxOkJBIOCbNcwCoZXYCSMuBxG24tZj/hGhJbJP+c0Ai3XB2+gdCWswYIVqS2aQZDkgkyEvnELCF51yyZENamuEMnmdskj0HJAw3SOcUHEgwwOMX9t6DHxtsbOQl2NOfSfw4UCcvPzt984cPFXZyuLRgAgOwSgNilYOAfAMpqkfBKBgFo2AkAAC/G1xVz4fdmAAAAABJRU5ErkJggg==","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":true,"prefix":"","firstName":"Roberto","middleName":"Ulises Cruz","lastName":"Neri","suffix":""},{"id":555908718,"identity":"7d97aaf7-5acd-412c-b5be-e3bbf12c3f0c","order_by":1,"name":"Jesús Alonso Valenzuela Pérez","email":"","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Jesús","middleName":"Alonso 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Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Carolina","middleName":"Vázquez","lastName":"Iñiguez","suffix":""},{"id":555908725,"identity":"50b901c7-4f7e-44d1-9013-87ba86e37e8d","order_by":8,"name":"María Luisa López Ibañez","email":"","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"María","middleName":"Luisa López","lastName":"Ibañez","suffix":""},{"id":555908726,"identity":"b6495cf0-ace4-4429-a3dd-5a21cd71b38b","order_by":9,"name":"Lucila Zárate Martínez","email":"","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Lucila","middleName":"Zárate","lastName":"Martínez","suffix":""},{"id":555908727,"identity":"b6e9674b-8c57-4ea4-bf24-77c7a50096d9","order_by":10,"name":"Atziri Buenrostro Fernández","email":"","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Atziri","middleName":"Buenrostro","lastName":"Fernández","suffix":""},{"id":555908728,"identity":"5fa43ac5-f72a-4416-b56c-85f1fedbda7e","order_by":11,"name":"Luis Antonio Ruiz Mares","email":"","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Luis","middleName":"Antonio Ruiz","lastName":"Mares","suffix":""},{"id":555908729,"identity":"a58d010d-1b11-4896-b301-7b038f50419e","order_by":12,"name":"Samantha Michelle Delgadillo Barajas","email":"","orcid":"","institution":"Hospital Civil de Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Samantha","middleName":"Michelle Delgadillo","lastName":"Barajas","suffix":""},{"id":555908730,"identity":"11f8ae83-702a-4c9c-8ed6-75b1bb1e1f25","order_by":13,"name":"Alma Abigail Díaz Pérez","email":"","orcid":"","institution":"Hospital Civil de 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Guadalajara","correspondingAuthor":false,"prefix":"","firstName":"Mariana","middleName":"Barba","lastName":"Anaya","suffix":""}],"badges":[],"createdAt":"2025-12-04 18:53:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8282068/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8282068/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":97701579,"identity":"5e9e15ed-2854-47ad-8b82-bdbcb6335a28","added_by":"auto","created_at":"2025-12-08 12:24:04","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":132526,"visible":true,"origin":"","legend":"","description":"","filename":"BMCGASTROENTEROLOGYPREPARATIONINCOLONOSCOPY.docx","url":"https://assets-eu.researchsquare.com/files/rs-8282068/v1/7ee0620dcf477d05d57ec849.docx"},{"id":97701578,"identity":"2519f376-9a14-49c1-a61d-d5e8f96e16de","added_by":"auto","created_at":"2025-12-08 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1","display":"","copyAsset":false,"role":"figure","size":63140,"visible":true,"origin":"","legend":"\u003cp\u003eParticipant flow diagram\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8282068/v1/594017b370e6c9018083d9b0.png"},{"id":105212357,"identity":"b47de8f1-6b0d-4680-82d5-b2bd82674452","added_by":"auto","created_at":"2026-03-23 13:58:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":791765,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8282068/v1/c496784b-75f5-4170-b05f-163b22a1589f.pdf"},{"id":97701597,"identity":"e3006743-dfaa-4d0c-abca-39a896b72926","added_by":"auto","created_at":"2025-12-08 12:24:07","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":55907,"visible":true,"origin":"","legend":"","description":"","filename":"Graphic1.docx","url":"https://assets-eu.researchsquare.com/files/rs-8282068/v1/3c22a6485f9558a23b6bddb7.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eBowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study\u003c/p\u003e","fulltext":[{"header":"Background","content":"\u003cp\u003eColonoscopy is the gold standard for the detection, diagnosis, and prevention of colorectal cancer, as it allows complete visualization of the colonic mucosa, identification and removal of premalignant lesions, and diagnosis of early-stage neoplasia.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e Its diagnostic and therapeutic effectiveness, however, depends fundamentally on the quality of bowel preparation.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003eSuboptimal cleansing impairs visualization, decreases adenoma detection rates (ADR), prolongs procedure time, increases healthcare costs, and is associated with a higher risk of post-colonoscopy colorectal cancer (PCCRC).\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e Moreover, inadequate preparation frequently requires repeating the procedure and results in a less satisfactory patient experience.\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eAchieving adequate bowel cleansing requires not only selecting an effective preparation regimen but also ensuring proper patient education, adherence to dietary restrictions, and optimizing the timing of the last dose.\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e Current evidence indicates that the interval between the final dose of the preparation and the start of colonoscopy plays a pivotal role in cleansing quality.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e The European Society of Gastrointestinal Endoscopy recommends an interval of no more than four hours, while expert consensus suggests an optimal window of 3\u0026ndash;8 hours, regardless of the specific preparation used.\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e Likewise, low-residue diets are generally better tolerated than clear-liquid diets and may contribute to improved cleansing efficacy, although evidence remains insufficient to recommend one specific diet or duration.\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eBowel preparations are frequently categorized as osmotic or polyethylene glycol (PEG)-based solutions. \u003csup\u003e9,10\u003c/sup\u003e PEG regimens are widely used and considered the standard preparation due to their safety, non-absorbable nature, and metabolic neutrality.\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e Osmotic alternatives (including sodium phosphate, magnesium citrate, mannitol, and lactulose) act by increasing water retention or stimulating secretion in the colon.\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e Among these, Lactulose has gained attention for its tolerability, palatability, and accessibility, positioning it as a potential alternative to PEG.\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e Nevertheless, studies comparing PEG and lactulose have produced mixed findings, with variability in reported efficacy, adverse effects, and patient satisfaction.\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eTo standardize the assessment of bowel cleansing, guidelines recommend the use of validated scoring systems such as the Aronchick Bowel Preparation Scale (ABPS), the Ottawa Bowel Preparation Scale (OBPS), the Boston Bowel Preparation Scale (BBPS), and the Harefield scale.\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e Each offers specific advantages and limitations, and their systematic use strengthens quality monitoring and reporting.\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e Despite the availability of effective regimens and validated scales, up to 20\u0026ndash;25% of patients still present with inadequate preparation, underscoring the influence of modifiable risk factors such as dietary adherence, dosing regimen, comorbidities, concomitant medications, hospitalization, and advanced age.\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eInadequate bowel preparation also adversely impacts key quality indicators, including ADR, cecal intubation rate, and withdrawal time.\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e Since ADR is recognized globally as the most important colonoscopy quality indicator (given its strong association with reductions in PCCRC incidence, advanced PCCRC, and PCCRC-related mortality) improving bowel preparation remains a clinical priority.\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e Furthermore, suboptimal cleansing increases the likelihood of missed flat or serrated lesions, shortens surveillance intervals, prolongs hospital stays, and may render screening colonoscopy less cost-effective.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eGiven the persistent rates of inadequate preparation and the need to optimize patient tolerability and adherence, further comparative evaluation of available bowel preparations is warranted.\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e In this context, polyethylene glycol and lactulose represent two commonly used but mechanistically distinct alternatives.\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e Comparing their impact on cleansing quality, endoscopic performance, tolerability, adverse effects, and patient experience is essential to guide clinical decision-making and improve the effectiveness of colonoscopy as both a diagnostic and preventive tool.\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e,\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eMain objective\u003c/h2\u003e\u003cp\u003eTo compare bowel preparation with Lactulose versus Polyethylene Glycol as the optimal agent for performing high-quality colonoscopies at the Hospital Civil Fray Antonio Alcalde and Hospital Civil Juan I. Menchaca, during the period from July 1, 2024, to July 31, 2025.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eDesign\u003c/h3\u003e\n\u003cp\u003eThis was a randomized, multicenter, double-blind clinical trial conducted in the colorectal surgery departments of the Hospital Civil Fray Antonio Alcalde and Hospital Civil Juan I. Menchaca (Guadalajara, Mexico) between August 2024 and July 2025. A total of 449 patients met the inclusion criteria, aged\u0026thinsp;\u0026ge;\u0026thinsp;18 years, with a valid indication for scheduled colonoscopy, and capable of providing informed consent.\u003c/p\u003e\u003cp\u003e Participants were randomly assigned to one of two bowel preparation groups: Lactulax\u0026reg; (Lactulose): 178 patients and Nulytely\u0026reg; (Polyethylene Glycol, PEG): 271 patients\u003c/p\u003e\u003cp\u003eExclusion criteria included a history of intestinal obstruction, known intolerance to lactulose or PEG, pregnancy or breastfeeding, and comorbidities potentially interfering with study participation. Additional elimination criteria were voluntary withdrawal, inability to complete colonoscopy, or significant intolerance to the assigned preparation.\u003c/p\u003e\n\u003ch3\u003eProcedure\u003c/h3\u003e\n\u003cp\u003eFollowing randomization, patients received instructions regarding dietary restrictions and the preparation regimen according to their assigned group. Tolerability, gastrointestinal adverse events, and adherence were monitored during the preparation. Colonoscopy was subsequently performed using standard techniques, and bowel cleansing quality was assessed with the Boston Bowel Preparation Scale (BBPS).\u003c/p\u003e\u003cp\u003eQuantitative variables (age, coagulation time, withdrawal time) were compared using the Student\u0026rsquo;s t-test for independent samples, after assessing normality (Kolmogorov-Smirnov) and homogeneity of variances (F-test). Categorical variables (sex, comorbidities, cecal intubation) were analyzed using the chi-square test. A baseline description of both groups was also performed in terms of age, sex, and comorbidities.\u003c/p\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eThe validated dataset was imported into IBM SPSS v25 for statistical analysis. Descriptive statistics were used to summarize the characteristics of the study population. Quantitative variables, including age, coagulation time, and withdrawal time, were compared between groups using the Student\u0026rsquo;s t-test for independent samples, after assessing normality (Kolmogorov-Smirnov) and homogeneity of variances (F-test). Categorical variables, such as sex, comorbidities, and cecal cannulation, were analyzed using the chi-square test to evaluate independence between groups. Statistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, and the analyses provided a basis for drawing evidence-based conclusions.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 606 patients were included, of whom 449 met the inclusion criteria and underwent colonoscopy in the colorectal surgery services of two different hospital units: the Old Civil Hospital of Guadalajara \u0026ldquo;Fray Antonio Alcalde\u0026rdquo; and the Civil Hospital \u0026ldquo;Juan I. Menchaca,\u0026rdquo; in Guadalajara, Jalisco, Mexico. All patients signed an informed consent form. Subsequently, a randomization process was carried out, assigning participants to two different bowel preparation groups: Lactulax\u0026reg; (Lactulose): 178 patients, and Nulytely\u0026reg; (Polyethylene Glycol): 271 patients (Figure 1)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe analysis was performed using IBM SPSS v25. To compare quantitative variables (age, coagulation time, withdrawal time) between both groups, the Student\u0026rsquo;s t-test for independent samples was used. Assumptions of normality (Kolmogorov-Smirnov) and homogeneity of variances (F-test) were evaluated. Categorical variables (sex, comorbidities, cannulation) were analyzed using the chi-square test to assess independence between groups.\u003c/p\u003e\n\u003cp\u003eA baseline description of the groups was conducted in terms of age, sex, and comorbidities (Table 1). Both age and sex showed a similar distribution between patients prepared with Lactulose and those prepared with Polyethylene Glycol. No statistically significant differences were identified in either of these parameters, supporting that both groups are comparable in terms of baseline demographic characteristics and were balanced with respect to these variables. The two groups were clinically similar in all comorbidities and study indications, except for LGIB (lower gastrointestinal bleeding), which was significantly more frequent in the group that received Polyethylene Glycol bowel preparation. However, this factor does not influence the results related to the Boston score or adenoma detection, and therefore, we consider it does not have relevant weight in this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 1.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Demographic characteristics, comorbidities, and study indications in bowel preparation using Lactulose vs. Polyethylene Glycol.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(N: 178)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene glycol (N:271)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e57.65\u003c/p\u003e\n \u003cp\u003e(\u0026plusmn; 13.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e55.62\u003c/p\u003e\n \u003cp\u003e(\u0026plusmn; 14.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.122\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMale sex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e69 (38.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e107 (39.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.921\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eFemale sex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e109 (61.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e164 (60.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003eComorbidity\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDiabetes Mellitus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e40 (22.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e50 (18.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.335\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eHypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e44 (24.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e76 (28%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.448\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eHuman immunodeficiency virus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7 (3.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (1.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.123\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAny type of cancer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (2.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (1.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.718\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003eStudy indication\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLGIB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e63 (35.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e135 (49.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCRC screening\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e142 (79.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e214 (79%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.905\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIBD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (1.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (2.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.327\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDiverticula\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e11 (6.18%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14 (5.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.677\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n\u003c/table\u003e\n\u003cp\u003eIn the comparison of the macroscopic changes observed during the procedure\u0026mdash;specifically edema, hyperemia, or bleeding\u0026mdash;a frequency of 3.24% was identified in the group that received lactulose and 5.13% in the group that used polyethylene glycol (Table 2). However, no statistically relevant association was found (p = 0.364). These results indicate that the presence of macroscopic alterations was low in both groups and comparable between them, with no evidence that the type of bowel preparation influences the occurrence of these changes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 2.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Macroscopic changes during the procedure following bowel preparation with Lactulose vs. Polyethylene Glycol.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMacroscopic changes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose\u003c/p\u003e\n \u003cp\u003e(N:185)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene glycol\u003c/p\u003e\n \u003cp\u003e(N:273)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eEdema, hyperemia, bleeding\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (3.24%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14 (5.13%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.364\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eSimilarly, the effect on the ascending colon, transverse colon, and the total Boston score (Table 3), as well as on the descending colon (Table 4), and the overall score (Table 5, Grafic 1) was evaluated. These were analyzed separately due to the differences in the number of observations obtained in each of them.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 3.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Results of the comparison of the Boston Bowel Preparation Scale scores in the ascending and transverse colon segments using Lactulose vs. Polyethylene Glycol.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eSegment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose (N:174)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene glycol (N:263)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSD\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAscending colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; 0.648\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.98\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; 0.581\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eTransverse colon\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; 0.668\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; 0.540\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 4.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Results of the comparison of the Boston score in the descending colon segment using Lactulose vs. Polyethylene Glycol.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eSegment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose\u003c/p\u003e\n \u003cp\u003e(N:174)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene glycol\u003c/p\u003e\n \u003cp\u003e(N:260)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eP-value\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSD\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eDescending colon\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; .615\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.98\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; .660\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 5.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Results of the comparison of the total Boston score using Lactulose vs. Polyethylene Glycol for bowel preparation.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003eTotal Boston Score\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(N:175)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene Glycol\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(N:267)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eP-value\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eIC 95%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSD\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u0026plusmn; 1.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-0.42 \u0026ndash; 0.162\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026plusmn; 1.49\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eGraphic 1:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cem\u003eComparaci\u0026oacute;n of Bowel Preparation Scores (Lactulose vs. Polyethylene Glycol)\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eWith regard to colonoscopy, the rate of successful intubation of the ileocecal valve was compared\u0026nbsp;between both groups. In the Lactulose group, the success rate was 168 (94.4%), and in the Polyethylene Glycol group it was 255 (94.1%), with a p-value of 0.85. Likewise, the mean cecal intubation time showed no statistically significant differences. (Table 7).\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eCecum reached: 423 / 449 = 94.25%\u003c/li\u003e\n \u003cli\u003eInternational standard: \u0026gt;95%\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 6.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Comparison of cecal intubation time using Lactulose vs. Polyethylene Glycol bowel preparation.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCecal intubation time (seconds)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose (N: 178)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene glycol (N:271)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIC 95%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e658.16\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e( \u0026plusmn; 422.39 ) s\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e694.63\u003c/p\u003e\n \u003cp\u003e(\u0026plusmn; 453.8) s\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-47.26 \u0026ndash; 120.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe overall cannulation rate (94.25%) was slightly below the international standard (\u0026gt;95%), although still close to the optimal level. No significant differences were found between the preparations in terms of success rate or cecal intubation times.\u003c/p\u003e\n\u003cp\u003eRegarding the effect of the type of bowel preparation on the total number of polyps identified (Adenoma Detection Rate: ADR), whose mean values and statistics are shown below (Table 7), although the Polyethylene Glycol group showed a higher proportion of detected polyps, this difference did not reach statistical significance (p = 0.236). It cannot be concluded that either preparation improves the ADR in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 7.\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Adenoma Detection Rate (ADR): Positive polyp detection using Lactulose vs. Polyethylene Glycol bowel preparation.\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBowel preparation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAdenoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLactulose (N:178)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e47 (26.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e0.236\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePolyethylene glycol (N: 271)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e87 (32.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, two bowel preparation regimens, Lactulose and Polyethylene Glycol (PEG), were compared with the aim of determining whether significant differences existed in the quality of colonic cleansing, endoscopic parameters, and diagnostic yield, using a non-inferiority approach. The available literature has previously explored this comparison; for example, the clinical trial by Aliaga Ramos et al.\u003csup\u003e25\u003c/sup\u003e reported superiority of lactulose preparation, achieving higher polyp detection rates compared with PEG. These findings have generated interest regarding the potential diagnostic benefit of lactulose as an alternative to conventional PEG-based preparations.\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eIn line with this line of research, the randomized study published by Rashid et al.\u003csup\u003e27\u003c/sup\u003e directly compared lactulose with PEG in 40 patients and also found no significant differences in the quality of bowel preparation as measured by the Boston score. The authors reported similar values between groups (6.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.786 vs. 6.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.813; p\u0026thinsp;=\u0026thinsp;0.59), concluding that both options are equally effective in achieving adequate colon cleansing.\u003c/p\u003e\u003cp\u003eIn our analysis, the groups showed homogeneity in their demographic and clinical characteristics, which helps minimize bias and increases the certainty that the results can be attributed to the type of preparation used. The absence of differences in age, sex, and comorbidities indicates an adequate allocation process and balanced comparison between the groups.\u003c/p\u003e\u003cp\u003eRegarding the quality of bowel cleansing, no significant differences were found in the Boston Bowel Preparation Scale, either in individual segments or in the total score, suggesting equivalent efficacy between lactulose and PEG. This result is consistent with previous reports by both Aliaga Ramos\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e and Rashid et al.\u003csup\u003e27\u003c/sup\u003e, reinforcing the idea that lactulose is a valid alternative with outcomes comparable to PEG for optimizing endoscopic visualization.\u003c/p\u003e\u003cp\u003eSimilarly, cecal intubation showed equivalent rates between groups, with no significant differences in the technical success of the procedure or the time required. Although the overall intubation rate (94.25%) was slightly below the international standard (\u0026gt;\u0026thinsp;95%), it remained within the acceptable range, indicating that the choice of preparation did not affect endoscopic performance.\u003c/p\u003e\u003cp\u003eWith respect to diagnostic yield, no significant differences were observed in the ADR (Adenoma Detection Rate). Although the PEG group showed a slightly higher proportion of polyp detection, the lack of statistical significance suggests that this difference could be due to chance. This finding is consistent with the results of the study by Rashid et al. \u003csup\u003e27\u003c/sup\u003e, which also reported no differences in the detection of neoplastic lesions between lactulose and PEG.\u003c/p\u003e\u003cp\u003eThe only parameter that showed a significant difference was the indication for the procedure due to rectal bleeding, which was more frequent in the PEG group. However, this finding was not related to variations in the main outcomes and did not impact the quality of preparation or lesion detection; therefore, its clinical relevance is limited.\u003c/p\u003e\u003cp\u003eOverall, the results of the present study confirm that lactulose and polyethylene glycol are clinically equivalent options for bowel preparation prior to colonoscopy. Both demonstrated similar efficacy, tolerability, and diagnostic performance. These findings support the individualized selection of bowel preparation based on availability, patient tolerance, cost, and institutional resources, without compromising the quality or diagnostic utility of the procedure.\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe results of this study demonstrate that bowel preparation with Lactulose and Polyethylene Glycol provides equivalent performance across all evaluated parameters. The quality of bowel cleansing, measured using the Boston Bowel Preparation Scale, was similar in both groups, with no significant differences in any colon segment or in the total score. Likewise, endoscopic performance, including cecal intubation rate and intubation time, showed no differences between the two preparations, indicating that the choice of bowel preparation does not influence the technical ease of the procedure. Similarly, polyp detection and ADR were comparable, suggesting that neither preparation confers a diagnostic advantage over the other. Altogether, these findings support the conclusion that both preparations are clinically equivalent and can be used interchangeably in clinical practice, with the final choice depending on availability, patient tolerance, cost, and institutional criteria, without compromising procedure quality or diagnostic yield.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eHCFAA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eHospital Civil Fray Antonio Alcalde\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eHCJIM\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eHospital Civil Juan I. Menchaca\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePEG\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePolyethylene Glycol\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eBBPS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eBoston Bowel Preparation Scale\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eADR\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eAdenoma Detection Rate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eLGIB\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eLower Gastrointestinal Bleeding\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCRC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eColorectal Cancer\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIBD\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eInflammatory Bowel Disease.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to express their gratitude to the Hospital Civil \u0026ldquo;Fray Antonio Alcalde\u0026rdquo; and the Hospital Civil \u0026ldquo;Juan I. Menchaca\u0026rdquo; for their support in the development of this study. We extend our appreciation to Dr. Roberto Ulises Cruz Neri, Head of the Coloproctology Service at Hospital Civil \u0026ldquo;Fray Antonio Alcalde\u0026rdquo; and principal investigator of the project, and to Dr. Jes\u0026uacute;s Alonso Valenzuela P\u0026eacute;rez, Head of the Coloproctology Service at Hospital Civil \u0026ldquo;Juan I. Menchaca,\u0026rdquo; for their invaluable guidance and collaboration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eC.N.R.U. served as Head of the Coloproctology Service at one of the participating hospitals, acted as principal investigator, led the project, and coordinated the recruitment of the research team. V.P.J.A. served as principal investigator at the second participating hospital and contributed to the overall supervision of the study. Z.M.L. provided essential data and contributions derived from her thesis work. V.C.F.J., G.D.J.A., H.G.F., S.N.M.M., G.G.J.C., V.I.C., and L.I.M.L. contributed to the study design, identification and Inclusion of eligible participants, and critical revision of the manuscript for important intellectual content. B.F.A., R.M.L.A., D.B.S.M., D.P.A.A., G.L.E.G., P.L.B., and B.A.M. participated in protocol development, clinical data collection, statistical analysis, and manuscript editing. All authors reviewed and approved the final version of the manuscript for publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study did not receive financial support from any public, commercial, or non-profit funding agency.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study were recorded on standardized data collection sheets and subsequently stored in a secure, project-specific electronic database. Due to the presence of confidential patient information, full access to the dataset is restricted to the responsible investigators. De-identified data may be made available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval and participant consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study received approval from the Ethics and Research Committees of the Hospital Civil Fray Antonio Alcalde on April 25, 2025, under the Institutional Protocol Identifier 131/25. The protocol was also submitted and registered at ClinicalTrials.gov (Registration No. NCT06666556). Written informed consent was obtained from all participants prior to undergoing colonoscopy, with clear explanation of the study objectives, potential risks, and anticipated benefits. The investigation was conducted in accordance with the Mexican General Health Law pertaining to health research, as well as the ethical principles outlined in the Declaration of Helsinki (2013) and the Nuremberg Code (1947).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupported by\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted without financial assistance from any public or private institution.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003e Hospital Civil \u0026ldquo;Fray Antonio Alcalde\u0026rdquo; Coronel Calder\u0026oacute;n 777, El Retiro, 44200 City Guadalajara, State \u0026nbsp;Jalisco, Country M\u0026eacute;xico.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e2\u003c/sup\u003e Hospital Civil \u0026ldquo;Juan I. Menchaca\u0026rdquo; Salvador Quevedo y Zubieta 750, Independencia Oriente, 44340 City Guadalajara, State Jalisco, Country M\u0026eacute;xico.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eKim SY, Kim HS, Park HJ. Adverse events related to colonoscopy: Global trends and future challenges. World J Gastroenterol. 2019;25(2):190-204. doi:10.3748/wjg.v25.i2.190\u003c/li\u003e\n \u003cli\u003eSullivan JF, Dumot JA. Maximizing the Effectiveness of Colonoscopy in the Prevention of Colorectal Cancer. Surg Oncol Clin N Am. 2018;27(2):367-376. doi:10.1016/j.soc.2017.11.009\u003c/li\u003e\n \u003cli\u003eTamai N, Adachi S, Sumiyama K. Bowel preparation for improving the quality of colonoscopy. Digestive Endoscopy. 2022;34(6):1134-1135. doi:10.1111/den.14339\u003c/li\u003e\n \u003cli\u003eSeward E. Recent advances in colonoscopy. F1000Res. 2019;8. doi:10.12688/f1000research.18503.1\u003c/li\u003e\n \u003cli\u003eParra-Blanco A, Ruiz A, Alvarez-Lobos M, et al. Achieving the best bowel preparation for colonoscopy. World J Gastroenterol. 2014;20(47):17709-17726. doi:10.3748/wjg.v20.i47.17709\u003c/li\u003e\n \u003cli\u003eLi CX, Guo Y, Zhu YJ, et al. Comparison of polyethylene glycol versus lactulose oral solution for bowel preparation prior to colonoscopy. Gastroenterol Res Pract. 2019;2019. doi:10.1155/2019/2651450\u003c/li\u003e\n \u003cli\u003eHassan C, East J, Radaelli F, et al. Bowel preparation for colonoscopy: European society of gastrointestinal endoscopy (esge) guideline-update 2019. Endoscopy. 2019;51(8):775-794. doi:10.1055/a-0959-0505\u003c/li\u003e\n \u003cli\u003eShahini E, Sinagra E, Vitello A, et al. Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature. World J Gastroenterol. 2023;29(11):1685-1707. doi:10.3748/wjg.v29.i11.1685\u003c/li\u003e\n \u003cli\u003eWallace SK, Bakkum-Gamez JN. Bowel Preparation. The ERAS\u0026Acirc;\u0026reg; Society Handbook for Obstetrics \u0026amp; Gynecology. Published online April 17, 2023:31-39. doi:10.1016/B978-0-323-91208-2.00007-X\u003c/li\u003e\n \u003cli\u003eWenqi S, Bei Z, Yunrong W, et al. Lactulose vs Polyethylene Glycol for Bowel Preparation: A Single-Center, Prospective, Randomized Controlled Study Based on BMI. Clin Transl Gastroenterol. 2024;15(1):e00652. doi:10.14309/ctg.0000000000000652\u003c/li\u003e\n \u003cli\u003eZhang X, Chen Y, Chen Y, et al. Polyethylene glycol combined with lactulose has better efficacy than polyethylene glycol alone in bowel preparation before colonoscopy: A meta-analysis. Clinics (Sao Paulo). 2023;78:100172.\u0026nbsp;doi:10.1016/j.clinsp.2023.100172\u003c/li\u003e\n \u003cli\u003eDi Leo M, Iannone A, Arena M, et al. Novel frontiers of agents for bowel cleansing for colonoscopy. World J Gastroenterol. 2021;27(45):7748-7770. doi:10.3748/wjg.v27.i45.7748\u003c/li\u003e\n \u003cli\u003eXiong Z, Fang Y, Feng F, Cheng Y, Huo C, Huang J. 2L polyethylene glycol combined with castor oil versus 4L polyethylene glycol for bowel preparation before colonoscopy among inpatients. Medicine (United States). 2023;102(29):E34294. doi:10.1097/MD.0000000000034294\u003c/li\u003e\n \u003cli\u003eMENACHO AM, REIMANN A, HIRATA LM, GANZERELLA C, IVANO FH, SUGISAWA R. Double-blind prospective randomized study comparing polyethylene glycol to lactulose for bowel preparation in colonoscopy. ABCD Arquivos Brasileiros de Cirurgia Digestiva (S\u0026atilde;o Paulo). 2014;27(1):9-12. doi:10.1590/s0102- 67202014000100003\u003c/li\u003e\n \u003cli\u003eMillien VO, Mansour NM. Bowel Preparation for Colonoscopy in 2020: A Look at the Past, Present, and Future. Curr Gastroenterol Rep. 2020;22(6). doi:10.1007/s11894-020-00764-4\u003c/li\u003e\n \u003cli\u003eQuintero E, Alarc\u0026oacute;n-Fern\u0026aacute;ndez O, Jover R. Controles de calidad de la colonoscopia como requisito de las campa\u0026ntilde;as de cribado del c\u0026aacute;ncer colorrectal. Gastroenterol Hepatol. el 1 de noviembre de 2013;36(9):597\u0026ndash;605.\u003c/li\u003e\n \u003cli\u003eEndoscopia del intestino grueso (rectoscopia, rectosigmoidoscopia, colonoscopia) [Internet]. [citado el 9 de julio de 2024]. Disponible en: https://empendium.com/manualmibe/compendio/social/chapter/B34.V.26.2.3.\u003c/li\u003e\n \u003cli\u003eRam\u0026iacute;rez-Quesada W, Vargas-Madrigal J, Alfaro-Murillo O, Uma\u0026ntilde;a-Sol\u0026iacute;s E, Campos-Goussen C, Alvarado-Salazar M, et al. Indicadores de calidad para la realizaci\u0026oacute;n de colonoscopia. Acta M\u0026eacute;dica Costarric. marzo de 2019;61(1):37\u0026ndash;42.\u003c/li\u003e\n \u003cli\u003eHong SM, Baek DH. A Review of Colonoscopy in Intestinal Diseases. Diagnostics. el 27 de marzo de 2023;13(7):1262.\u003c/li\u003e\n \u003cli\u003eShahini E, Sinagra E, Vitello A et al. Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature. World J Gastroenterol. 2023;29(11):1685-1707. doi:10.3748/wjg.v29.i11.1685\u003c/li\u003e\n \u003cli\u003eS\u0026aacute;nchez-del-R\u0026iacute;o A, P\u0026eacute;rez-Romero S, L\u0026oacute;pez-Picazo J, Alberca-de-las-Parras F, J\u0026uacute;dez J, Le\u0026oacute;n-Molina J, et al. Indicadores de calidad en colonoscopia. Procedimiento de la colonoscopia. Rev Esp Enfermedades Dig. 2018;110(5):316\u0026ndash;26.\u003c/li\u003e\n \u003cli\u003eYadav J, Sawant G, Lal P, Bains L. Oral Lactulose vs. Polyethylene Glycol for Bowel Preparation in Colonoscopy: A Randomized Controlled Study. Cureus. Published online April 8, 2021. doi:10.7759/cureus.14363\u003c/li\u003e\n \u003cli\u003eParekh PJ, Oldfield EC, Johnson DA. Bowel preparation for colonoscopy: What is best and necessary for quality? Curr Opin Gastroenterol. 2019;35(1):51-57. doi:10.1097/MOG.0000000000000494\u003c/li\u003e\n \u003cli\u003eJagdeep J, Sawant G, Lal P, Bains L. Oral Lactulose vs. Polyethylene Glycol for Bowel Preparation in Colonoscopy: A Randomized Controlled Study. Cureus. 2021;13(4):e14363. doi:10.7759/cureus.14363\u003c/li\u003e\n \u003cli\u003eShahini E, Sinagra E, Vitello A et al. Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature. World J Gastroenterol. 2023;29(11):1685-1707. doi:10.3748/wjg.v29.i11.1685\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eSHI W, ZHANG J, LIU P. Effectiveness of Lactulose for Colonoscopy Preparation in Adults:A Meta-Analysis. Medical Research. 2023;5(1). doi:10.6913/mrhk.050104\u003c/li\u003e\n \u003cli\u003eAliaga Ramos J., et al. Comparaci\u0026oacute;n de lactulosa vs polietilenglicol en la preparaci\u0026oacute;n intestinal para colonoscopia. Ensayo cl\u0026iacute;nico aleatorizado.\u003c/li\u003e\n \u003cli\u003eRashid A., et al. Oral Lactulose vs. Polyethylene Glycol for Bowel Preparation in Colonoscopy: A Randomized Controlled Study. Cureus. 2021;13(5):e14841.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Graph","content":"\u003cp\u003eGraph 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"Bowel preparation, Colonoscopy, Lactulose, Polyethylene Glycol, Boston Bowel Preparation Scale, Cecal intubation rate, Adenoma Detection Rate","lastPublishedDoi":"10.21203/rs.3.rs-8282068/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8282068/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAdequate bowel preparation is essential to ensure optimal visualization during colonoscopy, directly influencing lesion detection rates, procedural success, and overall diagnostic performance. Although Polyethylene Glycol (PEG) is widely used as the standard preparation, Lactulose has emerged as a potential alternative due to its tolerability and availability. Evidence comparing their effectiveness has shown mixed results, and further evaluation is warranted. This multicenter, randomized, double-blind clinical trial aimed to compare Lactulose and Polyethylene Glycol in terms of bowel cleansing quality, endoscopic performance, and diagnostic yield.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOf 606 enrolled patients, 449 met inclusion criteria and were randomized to receive either Lactulose (n = 178) or Polyethylene Glycol (n = 271). Colonoscopies were performed at two tertiary hospitals. Demographic variables, comorbidities, and indications for colonoscopy were recorded. Statistical analysis was conducted using IBM SPSS v25. Quantitative variables were compared using the Student’s t test for independent samples, with assumptions of normality (Kolmogorov–Smirnov) and homogeneity of variances (F-test) verified. Categorical variables were analyzed with chi-square testing. The Boston Bowel Preparation Scale (BBPS) was used to assess bowel cleanliness in each colon segment and overall. Endoscopic outcomes (including cecal intubation rate, cecal intubation time, and macroscopic mucosal changes) were compared. Diagnostic yield was evaluated through the Adenoma Detection Rate (ADR).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBoth groups were statistically comparable at baseline in terms of age, sex, and comorbid conditions. Only the indication of lower gastrointestinal bleeding differed significantly, occurring more frequently in the PEG group; however, this imbalance did not influence key outcomes. Macroscopic mucosal changes such as edema, hyperemia, or bleeding were infrequent and showed no significant association with the type of preparation (3.24% vs. 5.13%; p = 0.364). Across colon segments (including ascending, transverse, and descending) the BBPS scores were nearly identical, with no statistical differences observed. The total BBPS score also showed comparable results (Lactulose: 7.21 ± 1.61 vs. PEG: 7.08 ± 1.49; p = 0.37; 95% CI –0.42 to 0.162), demonstrating equivalent cleansing efficacy.Endoscopic performance indicators were similarly consistent between groups. Cecal intubation rates were 94.4% for Lactulose and 94.1% for PEG (p = 0.85), aligning closely with international standards. Cecal intubation time showed no statistical difference. Diagnostic yield, assessed through ADR, revealed a nonsignificant trend toward higher detection in the PEG group (26.4% vs. 32.1%; p = 0.236). Overall, neither preparation demonstrated superiority in adenoma detection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis randomized, double-blind, multicenter clinical trial demonstrates that Lactulose and Polyethylene Glycol offer equivalent efficacy as bowel preparations for colonoscopy. Both agents resulted in comparable cleansing quality across all colon segments, similar cecal intubation rates and times, and no significant differences in adenoma detection. These findings support the use of Lactulose as a clinically valid alternative to PEG, allowing for flexibility in preparation choice based on patient tolerance, cost considerations, availability, and institutional preferences—without compromising procedural quality or diagnostic performance.\u003c/p\u003e","manuscriptTitle":"Bowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-08 12:23:22","doi":"10.21203/rs.3.rs-8282068/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":"2a937ca8-d3e2-4a12-9f42-6dae25a6c32f","owner":[],"postedDate":"December 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-23T13:58:10+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-08 12:23:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8282068","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8282068","identity":"rs-8282068","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}