How many people are affected by ulcerative colitis ?
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.