Probability of Developing Ulcerative Colitis

Ulcerative colitis (UC) affects approximately 600,000 to 900,000 Americans, with about 38,000 new cases diagnosed each year. The lifetime risk is approximately 0.5%, making it one of the two main forms of inflammatory bowel disease (the other being Crohn's disease).

UC typically develops between ages 15 and 30, though a second peak occurs between ages 50 and 70. The disease causes chronic inflammation and ulcers in the innermost lining of the large intestine and rectum. Symptoms include persistent diarrhea (often bloody), abdominal pain, urgency, and fatigue.

While the exact cause remains unknown, UC involves an abnormal immune response, likely triggered by environmental factors in genetically susceptible individuals. Family history increases risk significantly. Treatment typically involves aminosalicylates, corticosteroids, immunomodulators, and newer biologic therapies. About 25-30% of UC patients eventually require colectomy (surgical removal of the colon). UC also increases colorectal cancer risk after 8-10 years of disease.