Following proctectomy, a large empty pelvic space is created. A pelvic omental pedicle flap has two purposes: (1) fill the pelvic dead space and (2) exclude small intestine from the pelvis. If postoperative pelvic radiation is needed, the small intestine will be kept out of the treatment field. In the event of perineal wound dehiscence, the small intestine will not be exposed, thus preventing the complication of perineal enterocutaneous fistula.