Metronidazole: an alternate therapy for antibiotic-associated colitis.

The results of treatment of 13 consecutive cases of antibiotic-associated pseudomembranous colitis with oral metronidazole are described. The diagnosis was made by typical sigmoidoscopic appearance with a confirming characteristic colonic biopsy specimen and/or stools positive for Clostridium difficile cytotoxin. All patients responded with the disappearance of diarrhea between 1 and 5 days. Two patients experienced relapse when the therapy was discontinued. Our experience with metronidazole shows that it is an effective treatment for antibiotic-associated pseudomembranous colitis. The response to metronidazole treatment compares favorably with that usually obtained with vancomycin.