Intervention trial for colorectal cancer prevention by endoscopic polypectomy in patients with familial adenomatous polyposis -2

Interventions: Colonic polyps will be thoroughly removed by periodic colonoscopy.
Primary outcome(s): Whether or not a patient needs surgery on the large intestine during the intervention period. It includes not only the development of a polyp that cannot be removed endoscopically or that of large intestinal cancer, but also cases where a patient wishes to undergo resection of the large intestine because of discomfort of endoscopic examination, and cases where emergency surgery is performed because of perforation occurred during endoscopic treatment.
Study Design: Single arm Non-randomized