Inflammatory bowel disease

Alternative names
Inflammatory bowel disease; Regional enteritis; Ileitis; Granulomatous ileocolitis

Crohn’s disease is a chronic autoimmune disease that can affect any part of the gastrointestinal tract but most commonly occurs in the ileum (the area where the small and large intestine meet).

Causes, incidence, and risk factors

Autoimmune disorders occur when the immune system attacks the body’s own cells. In Crohn’s disease, these rogue immune cells attack the gastrointestinal system. The cause is unknown, but genetic factors seem to play a role.

Inflammation frequently occurs at the end of the small intestine that joins the large intestine, but the condition may affect any area of the digestive tract. As a result of the immune attack, the intestinal wall becomes thick, and deep ulcers may form. In addition to the bowel abnormalities, Crohn’s disease can also affect other organs in the body, causing:

  • Skin rash  
  • Fistulas (abnormal connections between bowel and adjacent organs or skin)  
  • Liver inflammation  
  • Joint disease (arthritis)  
  • Eye inflammation  
  • Kidney stones  
  • Clotting problems (deep vein thrombosis)

The disease may occur at any age, but adolescence and early adulthood are the periods of highest risk. The only known risk factors include a family history of Crohn’s disease, Jewish ancestry, and smoking. About 7 out of every 100,000 people will develop Crohn’s disease.


  • Abdominal pain  
  • Fever  
  • Diarrhea  
  • Loss of appetite  
  • Unintentional weight loss  
  • Abdominal mass  
  • Abdominal sounds (borborygmus, a gurgling or splashing sound heard over the intestine)  
  • Fatigue  
  • Gastrointestinal bleeding  
  • Foul-smelling stools  
  • Tenesmus (pain with passing stool)

Additional symptoms that may be associated with this disease include the following:

  • Bloody stools  
  • Joint pain  
  • Incontinence  
  • Swollen gums  
  • Constipation  
  • Abdominal fullness and gas

Signs and tests

A physical examination may reveal an abdominal mass or tenderness, skin rash, swollen joints or mouth ulcers.

  • Tests that show findings of Crohn’s disease       o Endoscopy, colonoscopy, or sigmoidoscopy with small bowel biopsy       o Small bowel follow through       o Barium enema       o Upper GI series  
  • Positive stool guaiac

A stool culture may be done to rule out other possible causes of the symptoms.

This disease may also alter the results of the following tests:

  • Fecal fat  
  • Liver function tests  
  • Albumin


Your health care provider may prescribe medications such as 5-aminosalicylate to control the inflammatory process. If this is not effective or if the case is severe, treatment may require corticosteroids and immunomodulators such as azathioprine or 6-mercaptopurine.

If you have abscesses or fistulas, your health care provider may prescribe antibiotics. Infliximab (an antibody to an immune chemical called TNF-alpha, which promotes inflammation) can be effective for patients with fistulous disease and those with moderate to severe disease.

If medical therapy is not effective, you may need surgery (see bowel resection) to remove a diseased or strictured segment of the bowel or to drain an abscess. However, unlike ulcerative colitis, surgical removal of a diseased portion of the intestine does not cure the condition.

No specific diet has been shown to improve or worsen the bowel inflammation in Crohn’s disease. An adequate intake of calories, vitamins, and protein is important.

Foods that worsen diarrhea should be avoided - specific food problems may vary from person to person. People who have blockage of the intestines may need to avoid raw fruits and vegetables. Some people have difficulty digesting lactose (milk sugar) and need to avoid milk products.

Expectations (prognosis)

This is a chronic disease characterized by periods of improvement followed by deterioration and increased symptoms. There is an increased risk of small bowel or colorectal carcinoma associated with this condition.


  • Fistulas in the following areas:       o Bladder       o Vagina       o Skin  
  • Bowel obstructions  
  • Abscess  
  • Nutritional deficiencies (particularly vitamin B12 deficiency)  
  • Complications of corticosteroid therapy  
  • Inflammation of the joints  
  • Erythema nodosum  
  • Pyoderma gangrenosum  
  • Lesions in the eye  
  • Impaired growth and sexual development in children

Calling your health care provider

Call for an appointment with your health care provider if symptoms worsen or do not improve with treatment or if new symptoms develop.

Johns Hopkins patient information

Last revised: December 4, 2012
by Harutyun Medina, M.D.

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