Question: What is (are) ulcerative colitis ?
Answer: Ulcerative colitis is a chronic disorder that affects the digestive system. This condition is characterized by abnormal inflammation of the inner surface of the rectum and colon, which make up most of the length of the large intestine. The inflammation usually causes open sores (ulcers) to develop in the large intestine. Ulcerative colitis usually appears between ages 15 and 30, although it can develop at any age. The inflammation tends to flare up multiple times throughout life, which causes recurring signs and symptoms. The most common symptoms of ulcerative colitis are abdominal pain and cramping and frequent diarrhea, often with blood, pus, or mucus in the stool. Other signs and symptoms include nausea, loss of appetite, fatigue, and fevers. Chronic bleeding from the inflamed and ulcerated intestinal tissue can cause a shortage of red blood cells (anemia) in some affected individuals. People with this disorder have difficulty absorbing enough fluids and nutrients from their diet and often experience weight loss. Affected children usually grow more slowly than normal. Less commonly, ulcerative colitis causes problems with the skin, joints, eyes, kidneys, or liver, which are most likely due to abnormal inflammation. Toxic megacolon is a rare complication of ulcerative colitis that can be life-threatening. Toxic megacolon involves widening of the colon and an overwhelming bacterial infection (sepsis). Ulcerative colitis also increases the risk of developing colon cancer, especially in people whose entire colon is inflamed and in people who have had ulcerative colitis for 8 or more years. Ulcerative colitis is one common form of inflammatory bowel disease (IBD). Another type of IBD, Crohn disease, also causes chronic inflammation of the intestines. Unlike ulcerative colitis, which affects only the inner surface of the large intestine, Crohn disease can cause inflammation in any part of the digestive system, and the inflammation extends deeper into the intestinal tissue.
Source: GHR

Question: How many people are affected by ulcerative colitis ?
Answer: Ulcerative colitis is most common in North America and Western Europe; however the prevalence is increasing in other regions. In North America, ulcerative colitis affects approximately 40 to 240 in 100,000 people. It is estimated that more than 750,000 North Americans are affected by this disorder. Ulcerative colitis is more common in whites and people of eastern and central European (Ashkenazi) Jewish descent than among people of other ethnic backgrounds.
Source: GHR