Recommendations for follow-up interval after colonoscopy with inadequate bowel preparation in a national colonoscopy quality registry

Background and Aims: Endoscopist recommendations regarding a repeat colonoscopy after inadequate bowel cleanliness have not been fully described. Our aim was to evaluate the timing of recommendations for repeat colonoscopy after inadequate bowel preparation using a large, national colonoscopy registry. Methods: We performed a cross-sectional analysis of all outpatient screening and surveillance colonoscopies among adults ages 50 to 75 reported in the GI Quality Improvement Consortium from 2011 to 2018. The primary outcome was a recommendation to repeat colonoscopy within 1 year. Secondary outcomes were recommendations based on indication of colonoscopy and colonoscopy findings and predictors of a recommendation to follow-up within 1 year. Results: There were 260,314 colonoscopies with inadequate bowel preparation performed at 672 different sites by 4001 endoscopists. Of these, 31.9% contained a recommendation for follow-up within 1 year. This did not differ meaningfully by examination indication. The severity of colonoscopy findings influenced the recommendations for follow-up (within 1 year in 84.0% of cases with adenocarcinoma, 51.8% with any advanced lesion, and 23.2% with 1-2 small adenomas). Younger age, more severe pathology, location in the Northeast, and performance by an endoscopist with an adenoma detection rate ≥25% were associated with recommendations for follow-up within 1 year. Conclusions: Only some colonoscopies with inadequate bowel preparation are recommended to be repeated within 1 year, which may have implications for potential missed lesions. Further understanding of reasons driving recommendations is an important next step to improving guideline-concordant colonoscopy practice.