The correct diagnosis may take some time. Ulcerative colitis rarely affects the small intestine except for the lower section, the ileum. The inflammation causes the colon to empty frequently, resulting in diarrhea. An estimated 250,000 Americans have ulcerative colitis. It occurs most often in young people ages 15 to 40, although children and older people sometimes develop the disease.
Ulcerative colitis affects males and females equally and appears to run in some families.
The most common symptoms of ulcerative colitis are abdominal pain and bloody diarrhea. Patients also may suffer fatigue, weight loss, loss of appetite, rectal bleeding, and loss of body fluids and nutrients. Severe bleeding can lead to anemia. Sometimes patients also have skin lesions, joint pain, inflammation of the eyes, or liver disorders. No one knows for sure why problems outside the bowel are linked with colitis.