2.2. Patients
At each institution, the on-site study investigators will enroll candidates who provide written informed consent, enter the required information into the electronic data collection system, verify that each candidate meets the eligibility criteria (i.e., the meets all inclusion criteria and none of the exclusion criteria), and register the candidate with the registration office. After confirming that the candidate meets the eligibility criteria, a registration number will be assigned. Once enrollment is complete, patients will be randomized 1:1 to undergo ESD using the S-O clip or conventional ESD. Patients will be stratified by 3 factors: ESD surgeon (trainee/expert), institution, and lesion site (rectum/colon).