Colitis Diarrhea, antibiotic associated colitis, ulcerative colitis, or ischemic colitis Normal Abnormal Clostridium difficile is a bacterium that can be found in the colon. It can cause low-grade Diarrhea or severe colitis. It most commonly occurs when an individual is placed on antibiotics. The antibiotics kill off the good bacteria in the colon, and allow room for Clostridium difficile bacterium to grow. In addition, it can be contagiously spread from one person to another, especially in hospital and nursing homes. Watery Diarrhea Lower abdominal cramps Abdominal tenderness Fever, lethargy, heart racing, and severe abdominal pain in severe infections Stool test for Clostridium difficile toxin Flexible Sigmoidoscopy with biopsy for severe cases (to make immediate diagnosis) X-Rays in severe cases to rule out severe colon dilation (megacolon) Discontinue antibiotic therapy if possible Metronidazole by mouth Metronidazole intravenously if unable to take by mouth Vancomycin by mouth Seek immediate medical attention. If left untreated, this can progress to electrolyte imbalances, colon perforation, and death. Ulcerative Colitis Ischemic Colitis Other infectious Diarrheas