Crohn’s disease is a chronic inflammatory disease of the intestines. It primarily causes ulcerations (breaks in the lining) of the small and large intestines, but can affect the digestive system anywhere from the mouth to the anus. It is named after the physician who described the disease in 1932. It also is called granulomatous enteritis or colitis, regional enteritis, ileitis, or terminal ileitis.

Crohn’s disease is related closely to another chronic inflammatory condition that involves only the colon called ulcerative colitis. Together, Crohn’s disease and ulcerative colitis are frequently referred to as inflammatory bowel disease (IBD). Ulcerative colitis and Crohn’s disease have no medical cure. Once the diseases begin, they tend to fluctuate between periods of inactivity (remission) and activity (relapse).

Inflammatory bowel disease affects approximately 500,000 to two million people in the United States. Men and women are affected equally. Americans of Jewish European descent are 4 to 5 times more likely to develop IBD than the general population. IBD has historically been considered predominately disease of Caucasians, but there has been an increase in reported cases in African Americans suffering from IBD. The prevalence appears to be lower among Hispanic and Asian populations. IBD most commonly begins during adolescence and early adulthood (usually between the ages of 15 and 35). There is a small second peak of newly-diagnosed cases after age 50. The number of new cases (incidence) and number of cases (prevalence) of Crohn’s disease in the United States are rising, although the reason for this is not completely understood.

Crohn’s disease tends to be more common in relatives of patients with Crohn’s disease. If a person has a relative with the disease, his/her risk of developing the disease is estimated to be at least 10 times that of the general population and 30 times greater if the relative with Crohn’s disease is a sibling. It also is more common among relatives of patients with ulcerative colitis.