Overview

Clostridioides difficile (klos-TRID-e-oi-deez dif-uh-SEEL) is a bacterium that causes an infection of the large intestine (colon). Symptoms can range from diarrhea to life-threatening damage to the colon. The bacterium is often referred to as C. difficile or C. diff.

Illness from C. difficile typically occurs after use of antibiotic medications. It most commonly affects older adults in hospitals or in long-term care facilities. In the United States, about 200,000 people are infected annually with C. difficile in a hospital or care setting. These numbers are lower than in previous years because of improved prevention measures.

People not in care settings or hospitals also can develop C. difficile infection. Some strains of the bacterium in the general population may cause serious infections or are more likely to affect younger people. In the United States, about 170,000 infections occur annually outside of health care settings, and these numbers are increasing.

The bacterium was formerly named Clostridium (klos-TRID-e-um) difficile.