Pouchitis following pelvic pouch operation for ulcerative colitis. Incidence, cumulative risk, and risk factors

This study was undertaken to assess the risk for pouchitis in patients with ulcerative colitis who underwent surgery with colectomy, restorative pelvic pouch, and ileoanal anastomosis and to evaluate possible factors predictive for pouchitis development.

All patients receiving a pelvic pouch because of ulcerative colitis at Huddinge University Hospital between 1980 and 1993 (n = 149; 89 men) were prospectively evaluated for symptoms suggestive of pouchitis. Diagnosis of pouchitis was based on occurrence of certain symptoms in combination with endoscopic findings. Pouchitis was divided into mild and severe, and the time span until the first attack of mild or severe pouchitis was calculated for each patient.

Median follow-up time was 54 (5-152) months. The absolute cumulative risk of developing mild pouchitis was 21, 26, and 39 percent at 6, 12, and 48 months, respectively. The corresponding cumulative risk of developing severe pouchitis was 9, 11, and 14 percent, respectively. Risk for both groups together was 51 percent at 48 months. The occurrence of pouchitis, calculated at six-month intervals after closure of the loop ileostomy, was highest (23.1 percent) during the first six months. Incidence during the next six-month period was 11.4 percent and then only 3.1 percent thereafter. Thirty-two patients (21.5 percent) had chronic continuous symptoms requiring long-term metronidazole treatment, and 14 (9.4 percent) of those had chronic severe pouchitis. In two patients, removal of the pouch and permanent ileostomy became necessary. Extracolonic manifestations and early onset of ulcerative colitis were predictive factors for developing pouchitis. Former smoking seemed to be a protective factor.

The risk for pouchitis was highest during the initial six-month period. Cumulative risk leveled off after two years but was substantial (51 percent) at four years. Less than 10 percent of patients had severe, chronic pouchitis, and only two patients (1.3 percent) had their pouches removed.