Loop ileostomy after ileal pouch-anal anastomosis--is it necessary? Construction of a loop ileostomy is usually advised in patients having an ileal pouch-anal anastomosis to minimize the complication of chronic pelvic sepsis. Formation and closure of a loop ileostomy was associated with a 41 percent and 30 percent complication rate, respectively, in a prospective series of 34 patients. This morbidity must now be assessed in relation to the benefits of avoiding temporary fecal diversion in restorative proctocolectomy. 