DOUBLE-BLIND CROSSOVER TRIAL OF METRONIDAZOLE VERSUS PLACEBO IN CHRONIC UNREMITTING POUCHITIS

Metronidazole has been used to treat pouchitis, but there are no contr olled data that show it is effective. Chronic unremitting pouchitis is a form of the disorder particularly difficult to manage. Diarrhea is the main symptom of pouchitis, which results from acute inflammation o f the mucosa of an ileal reservoir. To test the hypothesis that metron idazole (400 mg thrice daily for seven days) is no better than placebo at reducing stool frequency in chronic unremitting pouchitis, a doubl e-blind placebo-controlled crossover study has been performed. Thirtee n patients who had undergone restorative proctocolectomy for ulcerativ e colitis were studied. The diagnosis of pouchitis was based on clinic al, endoscopic, and histological criteria. At entry all patients had s ymptomatic pouchitis and were passing more than six stools/24 hr or ha d consistently bloody stools with at least four of six endoscopic crit eria of mucosal inflammation. The median frequency of defecation decre ased by 3 bowel actions/24 hr (conservative 95% confidence intervals 0 -4/24 hr) on metronidazole but increased by a median of 1/24 hr on pla cebo. The difference between the median number of bowel motions, when treatment with metronidazole was compared to placebo, was 4 motions/24 hr (P < 0.05) in favor of metronidazole. There was no significant cha nge in the endoscopic or histological grade of inflammation, in the se rum C-reactive protein level, or symptomatic scores. In a parallel stu dy, metronidazole did not alter stool frequency in asymptomatic patien ts without pouchitis who had endoscopically normal reservoirs (six pol yposis, six colitis). Metronidazole significantly reduces the frequenc y of defecation when compared with placebo in chronic pouchitis. The r eduction in stool frequency is, however, of limited symptomatic benefi t to the patient.