Underwater EMR (UEMR) is an emerging technique for endoscopic resection. The purpose of this research is to observ wether the UEMR for medium-sized pedunculated polyps is safe and effective.

Inclusion Criteria:

Patients age between 18-75 years old with pedunculated colonic polyps (measuring between 10 and 20mm), who willing to participate in this study.

Exclusion Criteria:

1. pregnancy,
2. inflammatory bowel disease,
3. familial polyposis
4. the use of anticoagulant therapy or antiplatelet therapy
5. the absence of informed patient consent.
6. Polyps showing signs of deep submucosal invasion

Outpatients or inpatients requiring polypectomy