Topic Overview

• Topic Overview
• Cause
• Symptoms
• What Happens
• What Increases Your Risk
• When To Call a Doctor
• Exams and Test
• Treatment Overview
• Prevention
• Home Treatment
• Medications
• Surgery
• Other Treatment

What is ulcerative colitis?

Ulcerative colitis is an inflammatory bowel disease (IBD) that causes inflammation and ulceration of the mucous membrane that lines the colon and rectum . It usually affects the left side of the colon (sigmoid colon) and the rectum, but it may occur mainly in the rectum (proctitis) or throughout the colon (extensive colitis or pancolitis).

The amount of colon affected usually—but not always—predicts the severity of the disease. Extensive colitis

tends to cause more severe symptoms than proctitis. However, some people have a large amount of the colon affected without having severe symptoms.

The most common inflammatory bowel diseases are ulcerative colitis and Crohn's disease . Ulcerative colitis is more common than Crohn's disease. For more information, see the topic Crohn's Disease.

In about 10% of people who have symptoms, neither Crohn's disease nor ulcerative colitis can be diagnosed. These people have a form of inflammatory bowel disease called indeterminate colitis, which doctors believe is a combination of Crohn's disease and ulcerative colitis.