Cold Snare Resection

This study will evaluate the efficacy and safety of cold snare polypectomy(CSP) and hot snare polypectomy(HSP) in the treatment of colorectal 4-9mm 0-Isp and 0-Ip polyps, and compare the complete resection rate, postoperative late bleeding rate, intraoperative bleeding rate, en bloc resection rate, operation time and the number of metal clips used. The conclusion of this study will help clinical doctor develop more effective resection strategies for colorectal 0-Isp and 0-Ip polyps, and provide more effective treatment for patients.