Compliance With Bowel Preparation and Its Influencing Factors in Patients Undergoing Colonoscopy: Cross-Sectional Study.

Background: Bowel preparation compliance is an important intervenable factor that affects bowel preparation quality, and improving compliance is an important way to optimize bowel preparation outcomes. Despite its importance, the compliance rate and its influencing factors have not been thoroughly evaluated. Objective: This study aimed to investigate the overall compliance with bowel preparation instructions in patients undergoing colonoscopy. Methods: From September 2024 to March 2025, a cross-sectional questionnaire-based study was conducted at West China Hospital of Sichuan University, recruiting 740 participants via convenience sampling. We used an 8-item self-report scale to evaluate compliance with bowel preparation instructions. Items were rated on a 4-point Likert scale (0=completely noncompliant to 3=completely compliant), yielding a total score of 0-24. Higher scores reflected greater compliance, with ≥95% of the maximum score considered adequate compliance. Univariate analysis and multivariate logistic regression analysis were used to assess factors (age, educational level, knowledge of bowel preparation, satisfaction with the taste of the laxative, physical discomfort during bowel preparation) influencing bowel preparation compliance. Results: In this study, 42.0% (311/740) of patients demonstrated adequate compliance with bowel preparation instructions. In the univariate analysis, hypertension history, knowledge of bowel preparation, laxative type, satisfaction with the taste of the laxative, anxiety during bowel preparation, and physical discomfort during bowel preparation all had statistically significant influences. Multivariate analysis showed that older age (odds ratio [OR] 2.27, 95% CI 1.16-4.49), higher educational level (OR 3.29, 95% CI 1.41-8.33), adequate knowledge of bowel preparation (OR 1.59, 95% CI 1.14-2.24), satisfaction with the taste of the laxative (OR 2.11, 95% CI 1.48-3.02), and no physical discomfort during bowel preparation (OR 0.45, 95% CI 0.31-0.64) were key factors for adequate bowel preparation compliance. Conclusions: Personalizing bowel preparation instructions according to patients' age and education level, and selecting a laxative that suits the patients' taste preferences when available, are feasible ways to improve compliance with bowel preparation.