Ulcerative colitis (UC) is a chronic disease of the colon, or large intestine, which causes inflammation and ulceration (tiny open sores) of the inner lining of the colon and rectum.

In patients with UC, the body’s immune system reacts inappropriately. The body mistakes food, bacteria, or other matter in the colon as an invading substance, and it signals the immune system to attack the material, thus irritating the colon.

This irritation triggers a flare of UC symptoms. During a flare, people with UC may have bloody, pus-or-mucus filled diarrhea, cramping or abdominal pain, and bloating.

People with UC will experience times of “active disease,” or flares, alternating with periods of “remission,” or no symptoms.

UC affects approximately 500,000 people in the United States, and currently there is no cure. However, symptoms of UC can be successfully treated with existing medications.