Written recommendation to repeat colonoscopy within 1 year after inadequate bowel preparation: a simple and highly effective intervention

Background and study aim: When bowel preparation is inadequate, international guidelines recommend repeating the colonoscopy within 1 year. We aimed to evaluate the effectiveness of providing a written recommendation in improving completion of repeat colonoscopy within one year after inadequate bowel preparation. Patients and methods: We conducted a single-center, non-randomized clinical trial. Consecutive outpatients’ colonoscopies with inadequate bowel preparation were included. The intervention group received written recommendations concerning the necessity of repeating the colonoscopy within one year. Both groups were provided with verbal instructions conveying the same information. Inadequate bowel preparation was defined as the Boston Bowel Preparation Scale score <2 points in any segment. Results: 464 patients with inadequate bowel preparation were included. Adherence to repeat colonoscopy within 1 year was significantly higher in the intervention group compared with the control group (54.4% vs. 29.4%; p < 0.001). On repeat colonoscopy, the adenoma detection rate was 31.5% and 1.5% of patients were found to have colorectal cancer during repeat colonoscopies. In the multivariate analysis, provision of a written recommendation was the most strongly associated factor with completion of repeat colonoscopy within 1 year (OR 3,40; 95% CI 2.22-5.26; p < 0.001). Conclusion: Providing a written recommendation following inadequate bowel preparation improves completion of repeat colonoscopy within 1 year. Implementing a mandatory field in the colonoscopy report is an effective strategy to ensure patients undergo repeat colonoscopy in accordance with clinical guidelines. NCT05709145. Key words: inadequate bowel preparation, colonoscopy, written recommendation.