Crohn's disease

What is Crohn’s disease?

Crohn’s disease represents a form of GI tract inflammation. Inflammation from Crohn’s disease can affect any portion of the GI tract, from the mouth to the anus. Inflammation is typically patchy, and worse in certain areas than others. The section of the GI tract that connects the small intestine to the large intestine (the ileum) is the most commonly affected portion.

Inflammatory bowel disease and Crohn’s disease

Crohn’s disease is a form of inflammatory bowel disease (IBD). IBD is defined by chronic inflammation of the gastrointestinal (GI) tract and can be progressive. IBD is also associated with eye inflammation, skin issues, and joint pain or swelling. IBD can be confused with irritable bowel syndrome (IBS), a separate condition that is unrelated to GI inflammation.

What causes Crohn’s disease?

Crohn’s disease is thought to be caused by an overreaction from your immune system. The specific cause of Crohn’s disease is unknown but the state of your immune system, environmental factors, and your genetics can all impact the condition. Both men and women are affected equally. Around 20 percent of patients are diagnosed before age 20. Most people develop symptoms between the ages of 13 and 30.


Symptoms of Crohn’s disease can vary significantly from person to person and change depending upon the area of the GI tract that is irritated and inflamed.

General symptoms may include

  • Abdominal pain and cramping
  • Rectal bleeding
  • Frequent diarrhea
  • Reduced appetite and weight loss
  • Fatigue

Symptoms of severe Crohn’s disease may include fever, anemia, evidence of a bowel obstruction, vomiting, and severe weight loss.


If you are experiencing symptoms of Crohn’s disease, your doctor can perform a number of exams to look for inflammation in your GI tract. These include:

A small flexible tube with a camera can be inserted into many areas of your GI tract. A biopsy can also be done during this exam—where a cell sample is taken for testing.
Imaging tests
A CT or MRI can show abnormalities in the GI tract.


A wide range of treatment options can control symptoms of Crohn’s disease. With treatment, many Crohn’s patients successfully maintain remission or remain symptomless over a period of time. A flare-up is when symptoms appear again or suddenly worsen.

Medications that treat and control inflammation are the most common treatment method. The medication your doctor may prescribe will depend on how severe your Crohn’s is and where in the GI tract inflammation is present. Surgery is also an option to treat Crohn’s disease as it can help repair/remove damaged intestinal tissue and remove any blockages.

If you are experiencing symptoms of Crohn’s disease, see a health care provider.

Last reviewed: 
July 2018

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