What is Crohn’s disease?

Crohn’s disease, also called regional enteritis or ileitis, is a lifelong form of inflammatory bowel disease (IBD). The condition inflames and irritates the digestive tract — specifically the small and large intestines. Crohn’s disease can cause diarrhea and stomach cramps. It’s common to experience periodic disease flare-ups.

Crohn’s disease gets its name from American gastroenterologist Dr. Burrill Crohn (1884-1983). He was one of the first physicians to describe the illness in 1932. Ulcerative colitis is another commonly diagnosed IBD.

How common is Crohn’s disease?

An estimated half a million Americans have Crohn’s disease. This can include men, women and children.

Who might get Crohn’s disease?

Crohn’s disease typically appears in younger people – often in their late teens, 20s or early 30s. However, this condition can happen at any age. It’s equally common in men and women. Crohn’s disease can also be see in young children.

If you’re a cigarette smoker, your risk of Crohn’s disease might be higher than non-smokers.

What are the types of Crohn’s disease?

Crohn’s disease can affect different sections of the digestive tract. Types of Crohn’s disease include:

  • Ileocolitis: Inflammation occurs in the small intestine and part of the large intestine, or colon. Ileocolitis is the most common type of Crohn’s disease.
  • Ileitis: Swelling and inflammation develop in the small intestine (ileum).
  • Gastroduodenal: Inflammation and irritation affect the stomach and the top of the small intestine (the duodenum).
  • Jejunoileitis: Patchy areas of inflammation develop in the upper half of the small intestine (called the jejunum).

What causes Crohn’s disease?

There’s no known cause of Crohn’s disease. Certain factors may increase your risk of developing the condition, including:

  • Autoimmune disease: Bacteria in the digestive tract may cause the body’s immune system to attack your healthy cells.
  • Genes: Inflammatory bowel disease (IBD) often runs in families. If you have a parent, sibling or other family member with Crohn’s, you may be at an increased risk of also having it. There are several specific mutations (changes) to your genes that can predispose people to developing Crohn’s disease.
  • Smoking: Cigarette smoking could as much as double your risk of Crohn’s disease.

What are the symptoms of Crohn’s disease?

People with Crohn’s disease can experience periods of severe symptoms (flare-ups) followed by periods of no or very mild symptoms (remission). Remission can last weeks or even years. There’s no way to predict when flare-ups will happen.

If you have Crohn’s disease, symptoms you might have can include:

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy