Colectomy with ileoanal anastomosis has become a major surgical alternative for patients with ulcerative colitis and familial polyposis. Controversy has surrounded some technical aspects of the operation, including the necessity for rectal mucosal resection, the type of ileal pouch, and the need for a diverting ileostomy. This video will demonstrate our technique of colectomy, full transanal mucosal proctectomy, ileal J pouch-anal anastomosis, and diverting ileostomy, as performed in 375 patients.