Colitis will be defined as a history of Crohn's disease or ulcerative colitis with active diarrhea, active diarrhea due to Clostridium difficile infection, active diarrhea due to known or unknown cause with a stool specimen showing fecal leukocytes (if none has been done in such a patient this will be requested prior to enrollment). Diarrhea will be defined as more than three unformed bowel movements per day. The subject's primary physician will be asked to assess the subject's life expectancy, and subjects with an estimated life expectancy of less than one year as judged by the physician who knows him or her best will be excluded.