Crohn’s disease and ulcerative colitis (UC), both also known as inflammatory bowel diseases (IBD), are autoimmune diseases in which the body’s immune system attacks the intestines, resulting in intestinal inflammation, abdominal pain and bleeding.

Crohn’s disease and UC differ primarily in where the inflammation occurs. In UC, inflammation is contiguous and limited to the lining (or “mucosa”) of the colon. Crohn’s disease can be patchy, and can involve any location in the GI tract, but most commonly involves the last part of the small intestine (called the ileum) and the colon. Inflammation in Crohn’s can burrow beneath the mucosa, causing scarring, abscesses or leaking holes called fistulas.

IBD affects approximately 1.6 million Americans (1 in 200), evenly divided between Crohn’s disease and UC, and between men and women. These diseases usually appear in young people, leading to many years of suffering and disability. IBD is more common in northern latitudes, like the Pacific Northwest, where an estimated 50,000 patients are thought to reside. Some likely factors that contribute to this geographic effect are vitamin D deficiency from lack of natural sunlight, genetic predisposition in the North European/Scandinavian heritage, and unknown environmental triggers.