Crohn's Disease

Was this helpful?

What is Crohn’s disease?

Crohn’s disease is a chronic inflammation of the gastrointestinal tract and one form of inflammatory bowel disease. In Crohn’s disease, the body’s immune system mistakenly attacks healthy tissues in response to food or infection in the digestive tract. The disease can affect any part of the gastrointestinal tract, but it most commonly affects the lower portion of the small intestine (the ileum). Other areas affected include the mouth, esophagus, stomach, small intestine, large intestine, and rectum.

Symptoms often have an insidious onset and happen in intermittent bouts. The frequency and intensity of symptoms steadily progress over time. Delay in diagnosis is common due to the diverse pattern of symptoms. Classic symptoms of Crohn’s disease include abdominal pain and swelling and frequent episodes of diarrhea.

Crohn’s disease can seriously affect a person’s ability to participate in normal daily activities and can lead to serious complications including malnutrition and blockage in the intestines. Children who have Crohn’s disease may experience growth problems.

The exact cause of Crohn’s disease is not known, but researchers believe it may be an autoimmune disorder that tends to run in families. Crohn’s disease can affect all age groups but especially young adults ages 15 to 35.

Chronic inflammation of the gastrointestinal tract due to Crohn’s disease can lead to serious or life-threatening complications, such as nutritional deficiencies, gastrointestinal bleeding, anemia, and bowel obstruction.

Seek prompt medical care if you have symptoms of Crohn’s disease, such as abdominal pain and frequent diarrhea. Seek immediate medical care (call 911) if you, or someone you are with, have severe bleeding from the rectum, severe and constant abdominal pain, or an unusual change in alertness.


What are the symptoms of Crohn’s disease?

Symptoms of Crohn’s disease are due to the chronic inflammation and irritation of the gastrointestinal tract. Symptoms can range from mild to severe and include:

  • Abdominal pain and cramping (often involving the right lower quadrant)
  • Anemia
  • Eye discomfort and inflammation (uveitis)
  • Fever
  • Nutritional deficiencies
  • Pain with bowel movements
  • Recurring bouts of watery diarrhea that may include blood or pus
  • Weight loss

Serious symptoms that might indicate a life-threatening condition

In some cases, Crohn’s disease can lead to serious complications, such as dehydration, bowel obstruction, anemia, and peritonitis (infection of the lining that surrounds the abdominal cavity). Seek immediate medical care (call 911) if you, or someone you are with, are experiencing any of the following life-threatening symptoms:

  • Confusion or disorientation

  • High fever (higher than 101 degrees Fahrenheit)

  • Lethargy or unresponsiveness

  • Severe, constant abdominal pain or cramping that may occur with bloating, vomiting, constipation or diarrhea

  • Severe rectal bleeding or bloody stools

  • Unusual change in level of consciousness or alertness


What causes Crohn’s disease?

The exact cause of Crohn’s disease is not known, but researchers believe it may be due to an abnormal response of the immune system to an infection or food in the gastrointestinal tract. Crohn’s disease may also run in families.

Crohn’s disease is not caused by eating certain foods, although some foods can irritate the bowel and intensify symptoms in people who already have the disease. Irritating foods vary depending on the individual.

What are the risk factors for Crohn’s disease?

A number of factors increase the risk of developing Crohn’s disease. Not all people who are at risk for Crohn’s disease will develop the condition. Risk factors include:

  • Family history of Crohn’s disease

  • Jewish ancestry

  • Smoking

Reducing your risk of Crohn’s disease

You may be able to reduce your risk of Crohn’s disease by not smoking.


How is Crohn’s disease treated?

There is no cure for Crohn’s disease, but it can be treated. Treatment is aimed at minimizing symptoms and complications by reducing bowel inflammation and ensuring good nutrition and hydration. Following your individual treatment plan can produce long-term, symptom-free periods of remission.

Drug treatment of Crohn’s disease

Crohn’s disease can be treated with a variety of drugs including:

  • Anti-inflammatory drugs, such as mesalamine and sulfasalazine

  • Corticosteroids including prednisone. Corticosteroids are effective in controlling acute flare-ups but not in maintaining remissions. They can have serious side effects, such as increased susceptibility to infection, so they are generally used only in short courses.

  • Immune system suppressors, such as azathioprine and infliximab, which decrease gastrointestinal inflammation but can have serious side effects

  • Medications that have an anti-diarrheal effect, such as codeine and loperamide

  • Vitamins and other nutritional supplements to address or minimize nutritional deficiencies and malnutrition

Other treatments of Crohn’s disease

Crohn’s disease is also treated with a variety of therapies, lifestyle and dietary interventions, and possibly surgery. Other treatments of Crohn’s disease include:

  • Dietary changes, such as drinking extra fluids to prevent dehydration, eating a low-fat diet, and limiting dairy products and any other foods that seem to aggravate your symptoms

  • Getting regular exercise

  • Intravenous nutrition to ensure adequate nutrition if you are unable to eat because you need to let your gastrointestinal tract rest

  • Intravenous rehydration and electrolyte replacement if frequent diarrhea has resulted in the loss of excessive fluid and electrolytes, causing severe dehydration and electrolyte imbalances

  • Reducing stress

  • Regular medical care to monitor symptoms, modify treatment plans as needed, and watch for possible complications

  • Smoking cessation program if you smoke

  • Surgery to control Crohn’s disease in severe cases, such as when dietary and lifestyle changes and medications do not reduce severe symptoms or when there are complications, such as fistula formation. Surgical procedures include partial small bowel resection; partial colectomy, in which a portion of the colon is removed; or total colectomy, in which the entire colon is removed.

What are the possible complications of Crohn’s disease?

Complications of Crohn’s disease can be serious or life threatening. Complications can include:

  • Anemia
  • Bowel obstruction
  • Deterioration of bowel function
  • Disability
  • Fistulas, which are abnormal holes between the gastrointestinal tract and other areas of the body, such as the vagina, bladder and skin. Fistulas can easily become seriously infected and cause other problems.
  • Growth problems in children
  • Malnutrition
  • Peritonitis (infection of the lining that surrounds the abdominal cavity)
  • Rectal bleeding
  • Shock
Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2018 Oct 31
  1. Corticosteroids. Crohn’s and Colitis Foundation of America
  2. Tierney LM Jr., Saint S, Whooley MA (Eds.) Current Essentials of Medicine (4th ed.). New York: McGraw-Hill, 2011.
Explore Crohn's Disease
Recommended Reading
  • No one knows for sure what causes irritable bowel syndrome (IBS). What brings on its symptoms, though, is a bit clearer. How you eat and what you eat can make a difference. So can several things that have nothing to do with food. Knowing these triggers and what to do about them can help you manage your IBS.
    October 25, 2016
  • Most people don’t discover they have hepatitis C until many years after they became infected, so is it too late to treat?
    July 25, 2019
  • Blood in stool can take many forms: pooping blood, bright red blood in stool, bloody diarrhea, bloody mucus in stool. There can be several causes of blood in stool. Find out which ones aren't cause for concern and which ones mean it's time to see a doctor.
    April 2, 2018
Health Spotlight
Next Up
Answers to Your Health Questions
Trending Videos