The 5 Types of Crohn’s Disease

Along with ulcerative colitis, Crohn's disease is part of a group of diseases known as inflammatory bowel disease (IBD). There are five different types of Crohn's disease, each with its own set of symptoms. Here is information about Crohn's disease and the five types that you can use to help you discuss symptoms and treatment options with your doctor.

What is Crohn's disease?

Crohn's disease is a chronic illness in which the intestine or bowel become inflamed and ulcerated, or marked with sores.

Crohn's disease most commonly affects the lower part of the small intestine (ileum) and the colon. It can, however, occur in any part of the large intestine, small intestine, or stomach up to the mouth. It can affect people at any age but is most common in people who are between the ages of 15 and 30.

Crohn's disease can disrupt the normal function of the bowel in a number of ways. The bowel tissue may:

  • Swell, thicken, or form scar tissue, leading to blockage of the passageway inside the bowel
  • Develop ulcers that can involve the deep layers of the bowel wall
  • Lose its ability to absorb nutrients from digested foods, a condition called malabsorption
  • Develop abnormal passageways known as fistulas from one part of the bowel to another part of the bowel, or from the bowel to nearby tissues such as the bladder or vagina

What are the five types of Crohn's disease?

The five types of Crohn's disease and their symptoms are:

  • Ileocolitis: Ileocolitis is the most common type of Crohn's disease. It affects the small intestine, known as the ileum, and the colon. People who have ileocolitis experience considerable weight loss, diarrhea, and cramping or pain in the middle or lower right part of the abdomen.
  • Ileitis: This type of Crohn's disease affects the ileum. Symptoms are the same as those for ileocolitis. In addition, fistulas, or inflammatory abscesses, may form in the lower right section of the abdomen.
  • Gastroduodenal Crohn's disease: This form of Crohn's disease involves the stomach and duodenum, which is the first part of the small intestine. People with this type of Crohn's disease suffer nausea, weight loss, and loss of appetite. In addition, if the narrow segments of bowel are obstructed, they experience vomiting.
  • Jejunoileitis: This form of the disease affects the jejunum, which is the upper half of the small intestine. It causes areas of inflammation. Symptoms include cramps after meals, the formation of fistulas, diarrhea, and abdominal pain that can become intense.
  • Crohn's (granulomatous) colitis: This form of Crohn's disease involves only the colon. Symptoms include skin lesions, joint pains, diarrhea, rectal bleeding, and the formation of ulcers, fistulas, and abscesses around the anus.

There can be overlap between these types of Crohn's disease. Some people have more than one area of the digestive tract that is affected.


What causes Crohn's disease?

The cause of Crohn's disease is unknown. It is likely that Crohn's is at least partially an inherited disease that causes an abnormal response of the immune system in the gastrointestinal tract.

The first gene associated with Crohn's disease was the NOD2 gene (also known as the CARD15 gene). Abnormalities in this gene are found in up to one out of every five patients with Crohn's disease. Since then, at least 104 different genetic abnormalities have been shown to be associated with Crohn’s disease.

People who have a relative with Crohn's disease are 10 times more likely to develop the disease themselves. If the affected relative is a sibling, the risk jumps to 30 times more likely to develop Crohn's disease. Jewish people of European descent also have a greater risk for developing Crohn's disease.

How is Crohn's disease treated?

Treatment for Crohn's disease depends on the type and how severe the disease is. Because the disease can sometimes go into remission on its own, it is not always possible to determine whether a specific treatment has been effective. When Crohn's disease is active, treatment is aimed at relieving symptoms, controlling inflammation, and correcting nutritional deficiencies.

Medications are generally the first step in treating Crohn's disease. Some of these medications include anti-inflammatories, antibiotics, corticosteroids, antidiarrheals, and immune-suppressing medications. For those patients experiencing nutritional deficiencies, supplements are often prescribed.

Even though surgery cannot cure Crohn's disease, it is sometimes needed for patients whose symptoms do not respond to medications. Surgery can be performed to correct perforations, blockages, or bleeding in the intestine. Unfortunately, Crohn's disease often returns to the area next to where the inflamed part was removed. It is therefore important that you discuss with your doctor all possible options before deciding upon surgery.

What can I do to manage Crohn's disease?

In managing Crohn's disease, it is very important to maintain a healthy lifestyle. This is important even when the disease goes into remission for long periods of time. You can maintain a healthy lifestyle by exercising regularly and eating a healthy diet. Abstaining from smoking can also help prevent symptoms from recurring. Studies have shown that smokers are at a higher risk of developing Crohn's disease than nonsmokers and that smokers with Crohn's tend to have a more severe course than nonsmokers with Crohn's. People with Crohn's disease are usually able to lead healthy and active lifestyles.


Like many other disorders, understanding and being educated about Crohn's disease are the most important tools with which to manage it and prevent complications. The following organizations can provide more information about Crohn's disease:

Crohn's and Colitis Foundation of America

386 Park Avenue South, 17th Floor

New York, NY 10016


National Institute of Diabetes and Digestive and Kidney Diseases

2 Information Way

Bethesda, MD 20892


WebMD Medical Reference Reviewed by Jennifer Robinson, MD on October 23, 2017



Crohn's Colitis Foundation of America: "About Crohn's Disease."

National Digestive Diseases Information Clearinghouse: "Crohn's Disease."

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