Temporary diverting loop ileostomy is a generally accepted component of the ileal pouch-anal anastomosis (IPAA) procedure. Ileostomy closure is usually performed within two to three months but may be delayed because of disruption of the ileonanal anastomosis, suspected leak from the ileal reservoir, concomitant medical problems, or patient convenience. Of 362 patients undergoing IPAA at The Cleveland Clinic Foundation for inflammatory bowel disease, 10 have had their ileostomy closures delayed for more than six months. Clinical and manometric parameters are examined in these patients and compared with those who had earlier closure. There appears to be no significant difference in the functional outcome of IPAA in these patients in terms of number of bowel movements and degree of continence. Reservoir compliance and maximum tolerated volumes are similar. We conclude that delaying ileostomy closure for more than six months after IPAA has no deleterious effect on pouch function.