Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD). IBD is exactly what its name implies: a disease in which a part of the bowel (also called the colon, or large intestine) becomes inflamed. Doctors commonly use the term IBD to refer to just the 2 most common types: ulcerative colitis and Crohn’s disease (CD).
Crohn’s disease and ulcerative colitis share enough similarities that doctors sometimes have a hard time distinguishing between them. But while Crohn’s disease can affect any part of the digestive system, UC affects only the colon. Ulcerative colitis produces chronic inflammation and sores or ulcers along the inside lining of the colon.
The role of inflammation
Inflammation plays a big role in ulcerative colitis. Inflammation is the immune system’s normal response to infection or injury. In these circumstances, inflammation is a good thing—it walls off the injured or infected area and allows an increased blood supply to develop and help heal damaged tissue. As a result of this increased blood supply, the area gets warm and the surrounding tissue swells.
But in ulcerative colitis there is a “glitch” in the immune system, like a switch that gets stuck in the “on” position. Inflammation is constantly defending the body, even when there’s no foreign invader to fight off. This chronic inflammation can damage surrounding tissue, causing ulcers in the lining of the colon.
Who is affected by ulcerative colitis?
UC affects nearly 700,000 people in the United States. It can occur at any age, but it is typically diagnosed between the ages of 15 and 30. In addition, ulcerative colitis is also:
- Most common in the United States and Northern Europe
- 3 to 5 times more common in people of Eastern European Jewish descent
Causes of ulcerative colitis
The cause of ulcerative colitis is not known, but the most widely accepted theories point to a combination of factors. These include heredity, abnormalities of the immune system, and infections or other environmental triggers.
