The investigators will enroll subjects who receive screening or surveillance colonoscopy with small colorectal polyp, 4 to10 mm in size, from multiple centers in Taiwan. Subjects who are less than 20 years old and has contraindication will be excluded from this study. All the candidates for enrollment will sign the inform consent at the outpatient clinic. Once the candidate has the target lesion, polyp sized 4 to 10 mm, at colonoscopy will be randomized into either cold snaring or hot snaring polypectomy group. In the group with cold snaring, polypectomy will be done without electrocautery. In the hot snaring group, the polypectomy will be performed with electrocautery. The bowel preparation and colonoscopy insertion are the same in both groups as conventional colonoscopy method. The colonoscopy will be performed by experienced endoscopies who performed more than 100 polypectomies per year.