Overview of Crohn's Disease
Crohn's disease is an inflammatory bowel disease that causes swelling and ulcers (i.e., sores or lesions) in the lining of the intestinal tract, usually in the small intestine, colon, and/or anal area. Crohn's is an unpredictable, chronic illness that varies in severity. Some patients experience long periods of remission, and others do not.
Swelling and inflammation can occur in all layers of the intestinal lining, and diseased areas often can develop next to healthy areas, creating a "cobblestone" appearance in the intestines. Crohn's disease is not fatal, but the condition can cause extensive damage if it is not managed effectively.
Types of Crohn's Disease
Crohn's disease is classified by location. The most common type is ileocolitis, which develops in the small intestine and colon. Ileitis occurs in the small intestine only and Crohn's colitis affects the colon only. When the stomach and duodenum (the first part of the small intestine) are involved, the condition is called gastrodudenal Crohn's disease. Jejunoileitis refers to patchy inflammation in the upper portion of the small intestine.
Incidence and Prevalence of Crohn's Disease
It is estimated that 500,000 people in the United States have inflammatory bowel disease, and that Crohn's disease affects approximately 7 out of 100,000 people. This figure has increased over the past 50 years, and the United States now has one of the highest rates of Crohn's disease in the world.
Crohn's disease occurs in men and women almost equally, and can develop at any age. Onset between the ages of 15 and 35 is most common.
The disorder may be genetic (hereditary) and often runs in families. Up to 25 percent of patients who have Crohn’s disease have a relative who also has the disease. Having a relative with Crohn's disease increases the risk tenfold, and if the relative is a sibling, the risk is thirty times higher.
Crohn's disease is more prevalent in the United States and Europe. It is more common in urban communities and northern climates than in rural communities and southern climates. Crohn's disease affects Caucasians more often than other ethnic groups, but the rate is increasing among African Americans. Ashkenazi Jews of Eastern European heritage are four to five times more likely to develop Crohn's disease than the general population. The disorder is less common among Hispanics and Asian Americans.