Hydronephrosis: unrecognized complication following restorative proctocolectomy with ileal pouch-anal anastomosis

Restorative proctocolectomy with ileal pouch-anal anastamosis (IPAA) is the operation of choice to avoid permanent ileostomy in the surgical management of patients with ulcerative colitis and familial adenomatous polyposis coli. IPAA with two loops of small intestine (J-pouch) is the most common configuration. Mortality rates are low, and despite significant morbidity patient satisfaction remains high. Functional results are good in most cases. We present two cases of hydronephrosis following IPAA. Loin pain was the presenting symptom in both cases, with one patient developing impaired renal function. Hydronephrosis has not been reported following IPAA, but with other forms of pelvic and retroperitoneal surgery it is believed to remain largely asymptomatic. We discuss the etiology of this previously unrecognized complication and suggest that it may be more prevalent following IPAA than is realized.