P0274The efficacy and tolerability of ultra-low dosage polyethylene glycol based modified bowel preparation in patients with Uulcerative Colitis: A multicenter randomized controlled trial

Hui Xu1 Junmei Zhang2 Lin Liu3 Li Wang6 Wei Han6 Xinjuan Liu7 Yanjun Chen8 Yue Yang9 Zuoyan Wu10 Xuren Sun4* Linting Xun5* Hong Yang1* 1. Peking Union Medical College Hospital Chinese Academy of Medical Sciences & Peking Union Medical College 2. Beijing Rectum Hospital 3. The second Affiliated Hospital of Baotou Medical Colledge 4. The first Hospital of China Medical University 5. The First People’s Hospital of Yunnan Province 6. Chinese Academy of Medical Sciences & Peking Union Medical College 7. Beijing Chaoyang Hospital Capital Medical University 8. The First Affiliated Hospital of Soochow University 9. Heilongjiang Provincial Hospital 10. Beijing Sixth Hospital Background The incidence rate of ulcerative colitis (UC) in China is increasing during the past few decades. All UC patients need to undergo colonoscopy repeatedly for diagnosis, which all depend on adequate bowel preparation for a clear vision. While bowel preparation would be a burden for patients with UC, especially for those with severe activity. The aim of this study was to evaluate the efficacy, tolerability, and safety of the ultra-low dosage bowel preparation strategy for patients with UC. Methods We conducted a prospective multicenter randomized investigator-blinded non-inferiority trial. Patients diagnosed with UC aged from 18-70 years old were recruited. Patients were randomly assigned to receive 3L polyethylene glycol (PEG), or ultra-low dosage (1L) PEG with wholly enteral nutrition diet 1 day before plus glycerin enema before colonoscopy for bowel preparation. Efficacy were assessed by Boston Bowel Preparation Score (BBPS), with tolerability and safety assessed by questionnaires. Results Nine territory hospitals from different regions of China participated in this study from September 2022 to December 2024. A total of 155 patients in the 1L PEG group and 156 patients in the 3L PEG group were included in the analysis of BBPS. Disease extent, disease type, hematochezia, stool frequency, physician’s global assessment score, medication and laboratory test results didn’t differ significantly between two groups. The mean of BBPS in the 1L PEG group and 3L PEG group were 6.80 ± 1.57 and 7.24 ± 1.43, respectively (non-inferiority test, p = 0.0007). The tolerance score in 1L PEG group was significantly higher than 3L PEG group (8.28 ± 1.67 vs 7.63 ± 2.31, p = 0.001), and patients in 1L PEG group expressed a better willingness to accept the same bowel preparation method than 3L PEG group (“very willing” vs “acceptable”, p = 0.014). Nausea was the most common adverse reaction, followed by abdominal distension and thirsty. Patients in 3L PEG group had a significant higher proportion of nausea (28.0% vs 14.5%, p = 0.007), while had no significant in vomiting, abdominal distension, thirsty, abdominal pain and other reactions. Abdominal pain, diarrhea and hematochezia were not worsened either within 24 hours or 1 week in both groups. No patients were hospitalized due to bowel preparation or complications related to colonoscopy. Conclusion This multicenter RCT showed a non-inferior effect with a better tolerability and willingness to repeat of 1L PEG bowel preparation protocol than the traditional 3L PEG protocol in patients with UC. Very low-dosage (1L) PEG with 1 day total enteral nutrition diet plus glycerin enema before colonoscopy may be an adequate and more acceptable choice of bowel preparation. References: 1. Yang H, Zhou R, Bai X, et al. Trend and Geographic Variation in Incidence and Prevalence of Inflammatory Bowel Disease in Regions Across China: A Nationwide Employee Study Between 2013 and 2016. Frontiers in Medicine 2022;9. 2. Murthy SK, Feuerstein JD, Nguyen GC, et al. AGA Clinical Practice Update on Endoscopic Surveillance and Management of Colorectal Dysplasia in Inflammatory Bowel Diseases: Expert Review. Gastroenterology 2021;161:1043–1051.e4. 3. Chatterjee A, Kaur S, Jena A, et al. Strategies to Improve Colonoscopy Preparation in Inflammatory Bowel Disease. A Systematic Review and Network Meta-analysis of Randomized Trials. J Of Gastrointest And Liver Diseases 2024;33:245–253. 4. Megna B, Weiss J, Ley D, et al. Clear liquid diet before bowel preparation predicts successful chromoendoscopy in patients with inflammatory bowel disease. Gastrointest Endoscopy 2019;89:373–379.e2. Conflict of interest: Dr. Xu, Hui: No conflict of interest Yang, Hong: No conflict of interest