The Most Common Types of Crohn's Disease

Each Form Has Particular Symptoms and Presentations

Intestine In Crohn's Disease
Crohn's disease can cause the lining of the colon or the small intestine to look like a cobblestone street. Image BSIP/UIG / Getty Images

Crohn’s disease is an extremely complex disorder, made more so by the fact that the symptoms and complications can take different forms, depending on which part of your intestine is inflamed. While Crohn's disease can affect any part of the intestine, certain areas are affected more typically than others. Your physician may refer to your condition based on the primary area involved in your case.

The most common type of Crohn's disease are:

  • Ileocolitis
  • Ileitis
  • Crohn's (granulomatous) colitis
  • Gastroduodenal Crohn's disease
  • Jejunoileitis

Each form has a distinct presentation, differing symptoms, and a set of commonly associated complications.


The most common form is ileocolitis, which occurs in about 45 percent of people with Crohn's disease. This form of Crohn's disease affects the ileum (lower end of the small intestine) and the colon (large intestine).

Symptoms of this type of Crohn's disease can include diarrhea, cramping pain in the lower right or the middle abdomen, and significant weight loss. In some cases, the diseased areas in the ileum and the colon may be contiguous, affecting the valve that connects the small intestine to the large intestine, called the ileocecal valve.

Treatment for ileocolitis often includes a maintenance drug for continuation of remission, such as a 5-ASA (5-aminosalicylic acid) drug (mesalamine).

Faster-acting drugs such as steroids (prednisone, budesonide) might also be used in the case of a flare-up. Another type of medication that may be used are the anti-tumor necrosis factor drugs, which are reserved for patients with moderate to severe disease. Other medications that may sometimes be used include azathioprine, 6-mercaptopurine, or methotrexate.

Additionally, severe ileocolitis may require more intense treatment administered in the hospital setting, such as bowel rest (nothing to eat or drink) and enteral feeding (nutrition through a nasogastric tube) or parenteral feeding (intravenous nutrition).


Ileitis is the second most common form, affecting about 35 percent of patients with Crohn's disease. This type, also known as fistulizing or perforating Crohn's disease, affects only the ileum (the last part of the small intestine). Diarrhea, weight loss, cramping pain in the lower right or middle abdomen, and discomfort a few hours after eating a meal are common symptoms.

This type of Crohn's disease can cause malabsorption of vitamins or minerals. Two common nutritional deficiencies are the lack of vitamin B12 and the lack of folate. A lack of folate may prevent the creation of new red blood cells and therefore result in anemia. A vitamin B12 deficiency can result in a tingling in the fingers or toes (peripheral neuropathy) and can also contribute to the development of anemia.

Complications from ileitis can include fistulas or abscesses in the right lower quadrant.

Gastroduodenal Crohn's Disease

Gastroduodenal Crohn's disease, along with jejunoileitis, make up about 5 percent of all Crohn's disease cases.

This form of Crohn's disease affects the stomach and duodenum (the first part of the small intestine).

Symptoms include loss of appetite, weight loss, nausea, vomiting and pain in the upper middle abdomen. Vomiting may be a sign that there is an obstruction in a narrowed portion of the small intestine. This form of Crohn's disease is sometimes misdiagnosed as an ulcer, with the Crohn's disease only being discovered after treatment for the "ulcer" does not relieve symptoms or if active Crohn's disease is discovered in another section of the gastrointestinal tract.


This form of Crohn's disease is characterized by intermittent areas of inflammation in the jejunum, which is the middle, and longest section of the small intestine.

The jejunum is responsible for absorbing most nutrients from food.

Symptoms include crampy pain after meals, diarrhea, and abdominal pain that can vary from mild to intense. Complications of jejunoileitis include fistulas (an abnormal tunnel connecting two body cavities) and malnutrition caused by the poor absorption of nutrients.

Crohn's Colitis

Crohn's colitis, sometimes called granulomatous colitis, is a form of Crohn's disease that affects only the colon. This type of Crohn's disease affects 20 percent of patients. Crohn's colitis is often confused with ulcerative colitis, but there are two distinct differences between Crohn's colitis and ulcerative colitis:

  • Inflammation in ulcerative colitis is always contiguous, while in Crohn's colitis it is intermittent throughout the colon
  • Ulcerative colitis always affects the rectum while Crohn's colitis may not.

Symptoms of Crohn's colitis include diarrhea, bleeding from the rectum, and abscesses, fistulas, or ulcers around the anus. Peripheral arthritis and skin conditions associated with inflammatory bowel disease are found more frequently with Crohn's colitis than the other types of Crohn's disease.


Abbott Laboratories. "About Crohn's Disease." Abbott Laboratories 2013. 

Crohns and Colitis Foundation of America. "What is Crohn’s Disease?" 2012. 

Peppercorn, MA. "Patient information: Crohn's disease." 16 Oct 2012.