Clostridioides difficile (C. diff) is a bacterium responsible for causing severe diarrhea and more serious intestinal conditions such as colitis. It is often associated with antibiotic use, which can disrupt the normal bacterial flora of the colon, allowing C. diff to proliferate. The bacterium is more commonly found in healthcare settings, such as hospitals and long-term care facilities, making it a significant concern in these environments.

The bacteria produce toxins that attack the lining of the intestine, causing inflammation and, in severe cases, the formation of pseudomembranes. These are patches of tissue that can damage the walls of the intestine. In addition to gastrointestinal disturbances, the infection can lead to severe medical complications if not properly managed.