Colitis caused by Clostridium difficile: a review.

Recent evidence has incriminated a toxin-producing anaerobe, Clostridium difficile, as the causative agent of pseudomembranous colitis, an acute inflammatory bowel disease that generally occurs in association with antimicrobial therapy. A wide variety of antimicrobial agents appear to promote C. difficile infection and thereby precipitate colitis. Although the exact pathogenetic mechanisms are not known, several hypotheses, related to the ability of antibiotics to suppress competing bacteria and alter bacterial adhesion to intestinal mucosa, are explored in this review. Laboratory participation in the diagnosis of pseudomembranous colitis caused by C. difficile involves culture and toxin assay. Isolation of C. difficile from feces is facilitated by the use of recently developed selective media. Vancomycin is recommended for treatment of pseudomembranous colitis when removal of the offending antimicrobial agent does not result in clinical improvement.