A multicenter study on bowel preparation in inflammatory bowel disease patients: comparison between 1L-PEG-ASC and 2L-PEG regimens in an outpatient setting.

Background and aims: There is a paucity of data on which bowel preparation (BP) to use in an inflammatory bowel disease (IBD) outpatient setting, in particular after the introduction of 1L-PEG-ASC. Thus, we aimed to evaluate the most effective BP between 1L-PEG-ASC and 2L-PEG and to identify risk factors for inadequate BP in this IBD population.

Methods: This is a multicentric, retrospective, cross-sectional study including IBD patients aged >16 years, who underwent outpatient split-dose colonoscopy between January 2021 and December 2022. Boston Bowel Preparation Scale (BBPS) was used to determine the adequacy of BP. Multivariable logistic regression was fitted to compare BP adequacy between 1L-PEG-ASC and 2L-PEG.

Results: Overall, 506 patients (F 42.9%, mean age 48.9 ± 15.2 years) were included and BP was adequate in 440 (87.0%). 1L-PEG-ASC was associated with a higher rate of adequate BP compared to 2L-PEG (89.8% vs. 83.8%, P  = 0.048) and higher BBPS score [median 8, interquartile range (IQR): 7-9 vs. 6, IQR: 6-8, P  < 0.001]. Male sex ( P  = 0.03), previous ileal/colonic surgery ( P  = 0.01), and stricturing Crohn's disease (CD) ( P  = 0.01) were associated with inadequate BP. At multivariable analysis, 1L-PEG-ASC was a predictor of adequate BP [odds ratios (OR) = 1.70, 95% confidence interval (CI): 1.00-2.90, P  < 0.05]; whereas male sex (OR = 0.51, 95% CI: 0.29-0.90, P  = 0.02) and previous ileal/colonic surgery (OR = 0.40, 95% CI: 0.21-0.77, P  < 0.01) were confirmed as risk factors for inadequate BP.

Conclusion: Results from this large real-world cohort highlight the efficiency of 1L-PEG-ASC in providing better BP compared to 2L-PEG. However, further studies are needed to validate our retrospective results and confirm the superiority of 1L-PEG-ASC. Male sex and previous ileal/colonic surgery and stricturing CD were related to poor BP.