Crohn’s Disease: Overview

What is Crohn's disease?

Crohn's disease belongs to a group of conditions known as inflammatory bowel diseases (IBD). Crohn's disease is a chronic inflammatory condition of the gastrointestinal tract (GI tract). It is important to know that Crohn's disease is not the same thing as ulcerative colitis, another type of IBD. The symptoms of these two illnesses are quite similar but the areas affected in the gastrointestinal tract are different.

Crohn's disease may affect any part of the gastrointestinal (GI) tract, from the mouth to the anus. In children it frequently affects the large intestine, which is also called the colon.

Crohn's disease can cause inflammation, scarring and infection in the gastrointestinal tract.  It can also affect other organs including skin, eyes, bones and liver. Crohn's disease can lead to chronic anal fissures, small tears in the inner lining of the rectum, and infections around the anus. Crohn's disease can also cause fistulas, which are small tunnels that emerge from the intestine to connect to other loops of intestine and can lead to other medical problems.

While both Crohn's disease and ulcerative colitis are types of inflammatory bowel diseases (IBD), they should not be confused with irritable bowel syndrome (IBS), a disorder that affects the muscle contractions of the colon. IBS is different from chronic intestinal inflammation.

What causes Crohn's disease?

The causes of Crohn's disease are not well understood. Recent research suggests both hereditary and environmental factors contribute to the development of Crohn's disease.

The GI tract normally contains harmless bacteria, many of which help us digest food. In people with IBD, these bacteria are mistaken for harmful invaders and the body launches an immune system attack against them. Cells travel out of the blood to the intestines and produce inflammation, a normal immune system response to harmful bacteria. However, the inflammation does not subside, leading to persistent or chronic inflammation, ulceration, thickening of the intestinal wall and eventually causing symptoms. Diet and stress may aggravate Crohn's Disease, but they do not cause the disease on their own.

Who gets Crohn's disease?

Crohn's disease may affect as many as 1.4 million Americans. Men and women are equally likely to be affected. The disease can occur at any age, Crohn's disease is more prevalent among adolescents and young adults between the ages of 15 and 35. Although cases of Crohn's disease are rapidly on the rise in children under 10 years old and have been seen in children under 1 year old.

Crohn's disease tends to run in families, so if you or a close relative have the disease, your family members have a significantly increased chance of developing Crohn's. Studies have shown that 5% to 20% of affected individuals have a first  degree relative (parents, child or sibling) with one of the diseases. The risk is substantially higher when both parents have IBD.

The disease is most common among people of eastern European backgrounds, including Jews of European descent. In recent years, an increasing number of cases have been reported among African Americans.

Helpful resources

  • The Crohn's and Colitis Foundation of America has patient information, supports research and has community support programs for children and families who are affected by Crohn's Disease.
  • The Pediatric IBD Foundation explains more about IBD and Crohn's disease.
  • UC and Crohn's is a site especially for teens dealing with these IBD-related conditions.
  • Take Steps is a fundraising and advocacy group supporting people with Crohn's disease and ulcerative colitis.