Colitis due to Clostridium difficile has been increasingly recognized as a serious nosocomial problem. Recommended therapy is with metronidazole, 500 mg four times daily for 10 days. About 80% of patients respond to this therapy. However, the response may be be delayed, in which case debilitation due to diarrhea progresses. The 20% who do not respond tend to be sicker to start, and debilitation due to diarrhea is a severe problem. In reviewing the medical literature, we discovered that the earliest papers on C. difficile colitis emphasized symptomatic therapy with 'lomotil' (diphenoxylate with atropine).