Double blind controlled trial of oral vancomycin as adjunctive treatment in acute exacerbations of idiopathic colitis.

A prospective double blind trial of vancomycin vs placebo was undertaken in 40 consecutive adult patients with exacerbation of idiopathic colitis (33 ulcerative colitis, seven Crohn's disease). Vancomycin or placebo (500 mg six hourly) was given for seven days in addition to routine medical therapy. Although there was no significant overall difference in outcome between the two groups, there was a trend towards a reduction in the need for operative intervention in patients with ulcerative colitis treated with vancomycin compared with controls. The efficacy of vancomycin was not attributable to its known action against C difficile, which was not isolated from any of the patients. The data suggest that microbiological factors may play a part in the pathogenesis of ulcerative colitis and that further studies using antimicrobials are desirable.