Crohn's disease is one of the diseases called inflammatory bowel disease / IBD.  

In Crohn's disease, swelling and irritation can be found in the lining of the intestine. It can also involve the whole thickness of the bowel wall. Crohn's disease is usually in the lower part of the small intestine, called the ileum. However, it can affect any part of the digestive tract, from where food is taken in (the mouth) to where food comes out (the anus).

Gastrointestinal tract picture / illustration by Cincinnati Children's

Some patients with Crohn's disease have long periods of remission (when symptoms disappear). This may last months or years. However, there is no way to tell when a remission will happen or when disease symptoms will return. There is no cure for Crohn's disease.

About 1.4 million Americans have inflammatory bowel disease. People of all age groups can have Crohn's disease, but it usually begins in the late teens and early adulthood. Twenty percent of all Crohn's cases affect children.

The disease affects males and females equally, but Crohn's disease tends to run in families and certain ethnic groups. About 20 percent of people with Crohn's disease have a blood relative with some type of IBD. For those patients with a family history, it is very likely that Crohn's disease will begin in the teens and 20s.