Abstract: Objective To analyze the risk factors of delayed bleeding after colonic polyp resection.Methods 700 patients with colonic polyps admitted to General medical treatment Hanzhong 3201 hospital from January 2022 to May 2023 were included as the research object,and all patients were treated with colonoscopy polypectomy.According to whether Post-procedural bleeding (PPB) occurred after operation,they were divided into two groups:the group with PPB occurrence (n=85 cases) and the group without PPB occurrence (n=615 cases).The general data,clinical data and operation related data of the two groups were analyzed by univariate analysis.Multivariate Logistic regression was used to analyze the risk factors of postoperative PPB,and receiver operating characteristic curve was drawn to analyze the predictive value of risk factors.Results 700 patients in this study were all treated by colon polypectomy,and 85 patients (12.14%) developed PPB within 30 days after operation,that is,the incidence of PPB in this study was 12.14%.There was significant difference in sex,age,hypertension and treatment history of thrombosis between the two groups (P<0.05).There was significant difference in the morphology,diameter and surgical methods between the two groups (P<0.05).Multivariate Logistic regression analysis showed that polyp morphology (stalk),polyp diameter (>1cm),Endoscopic mucosal resection(EMR) and Endoscopic submucosal dissection(ESD) were the risk factors for postoperative PPB (P<0.05).The ROC curve showed that the area under curve of polypoid-shaped is 0.653,95%CI is 0.616-0.688,the AUC of polyp-diameter is 0.741,95%CI is 0.707-0.773;and in the way of operation,the AUC of argon plasma coagulation/ESD is 0.730,95%CI is 0.713-0.802,the AUC of EMR/ESD is 0.541,95%CI is 0.498-0.584,the AUC of APC/EMR is 0.604 and 95%CI is 0.565-0.641.Conclusion Polyp pedicled,diameter > 1cm,EMR and ESD are the risk factors for postoperative PPB.

Key words: colon polypectomy, delayed bleeding, argon plasma coagulation, endoscopic mucosal resection, endoscopic submucosal dissection, risk facto