This inner lining is called the mucosa. Significant deviations from this pattern may be a clue to the physician to suspect Crohn's disease rather than ulcerative colitis. Skip areas are patches of healthy tissue separating segments of diseased tissue. They are often seen in Crohn's disease, but rarely in ulcerative colitis. Inflammation of the rectum is called proctitis.
Inflammation involving the entire colon is termed pan-colitis.
The inflammation causes the colon to empty frequently resulting in diarrhea. As the lining of the colon is destroyed ulcers form releasing mucus , pus and blood. UC is relatively common in the western world and at least 250,000 in the United States alone have the disease. It occurs most frequently in people ages 15 to 30 although children and older people occasionally develope the disease. Altogether this area is also known as the ileocecal region.