Clostridium difficile colitis, also known as c. diff, is a type of bacterial infection that may affect the colon. The colon is the last portion of the gastrointestinal tract, which helps digest food and form stool. Clostridium difficile colitis can cause bloating, severe diarrhea, and abdominal pain. It is commonly related to overuse of antibiotics in older or hospitalized people. Physicians can diagnose clostridium difficile colitis by testing the stool for the bacteria or the toxins that it creates. Clostridium difficile colitis is treated with specific antibiotics to kill the bacteria, and other antibiotics are often stopped. Other newer treatments include probiotics and fecal transplants.