BACKGROUND: The association between delayed post-polypectomy bleeding and chronic kidney disease remains unclear. OBJECTIVE: This study investigated whether patients with chronic kidney disease are at an increased risk of delayed post-polypectomy bleeding. METHODS: This cohort study included patients who underwent colonoscopy and polypectomy in Korea between 2005 and 2022. We assessed various covariates, including patient-, polyp-, and procedure-related factors, using propensity score matching and inverse probability of treatment weighting to determine the impact of chronic kidney disease on delayed post-polypectomy bleeding risk. RESULTS: Out of 21,562 patients, 16,591 with 41,014 polyps were included in the analysis. Of these, 2057 (12.4%) had chronic kidney disease, with 894 in early-stage (stages 1 and 2) and 1163 in advanced-stage (stages 3-5). There were 14,534 individuals without chronic kidney disease. After propensity score matching, the risk of delayed post-polypectomy bleeding in patients with chronic kidney disease was significantly higher than that in the non-chronic kidney disease group (OR 1.80, CI 1.12-2.89, p = 0.01). The risk increased with chronic kidney disease stage (OR 2.38, 95% CI 1.01-5.64 for early stage
OR 2.80, 95% CI 1.20-6.51 for advanced stage, all p <
0.05). The results remained robust after inverse probability analysis. CONCLUSIONS: Chronic kidney disease is an independent risk factor for delayed post-polypectomy bleeding, even in the early stages. The risk correlates with the chronic kidney disease stage. Meticulous attention is imperative during polypectomy for all patients with chronic kidney disease, including those in the early stages.