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Crohn's Disease

What is Crohn's Disease

As many as two-thirds to three-quarters of people with Crohn's disease will require surgery at some point during their lives. While surgery does not cure Crohn's disease, it can conserve portions of your GI tract and return you to the best possible quality of life.

Crohn's disease causes inflammation, or swelling, and irritation of any part of the digestive tract—also called the gastrointestinal (GI) tract. The part most commonly affected is the end part of the small intestine, called the ileum, and the part of the large bowel (colon) attached to the ileum.

In Crohn's disease, the inflamed parts of the GI tract can become scarred (strictures) and cause blockage, or can cause penetration through the bowel wall causing inflamed tracts (fistulas) or infected pockets (abscesses). Both types of problems can cause pain and change in bowel habits.

Crohn's disease is one of two main forms of diseases of the GI tract named inflammatory bowel disease (IBD). The other form, called ulcerative colitis, only affects the large intestine, which includes the colon and the rectum—the lower end of the large intestine, leading to the anus.

Who Gets Crohn's Disease?

Both men and women can get Crohn's disease, and it can run in families. People with Crohn's disease may have a blood relative with the disease or another type of IBD. Crohn's disease can occur at any age, and most commonly starts in adolescents and young adults.


Researchers are studying the possible causes of Crohn's disease. Your body's natural defense system, called the immune system, protects you from infection by fighting against bacteria, viruses, and other things that can make you sick. Researchers believe that with Crohn's disease, the immune system is triggered by bacteria in the GI tract, leading to chronic inflammation and ulcers, or sores, and damage to the intestines. Other factors that researchers think are important in Crohn's disease are:

  • genes—the traits passed down from your parents
  • diet
  • stress
  • smoking


Crohn's disease symptoms can be different for each person. The most common symptoms of Crohn's disease are:

  • diarrhea
  • abdominal cramping and pain
  • weight loss


A doctor will perform a physical exam and tests to diagnose Crohn's disease.

The doctor may order blood tests, which can show anemia caused by bleeding. Anemia is a condition in which red blood cells are fewer or smaller than normal, which means less oxygen is carried to the body's cells. Blood tests can also show a high white blood cell count, a sign of chronic inflammation.

You may also be asked for a stool sample. A stool test is commonly used to rule out other causes of GI diseases, such as infections. Other tests may be needed to diagnose Crohn's disease. The following tests are all performed at a hospital or outpatient center.

  • Colonoscopy. Colonoscopy is the most commonly used test to specifically diagnose Crohn's disease. This test is used to look inside your rectum, entire colon, and ileum.
  • Upper GI endoscopy and enteroscopy. Your doctor uses these tests to see inside your upper GI tract.
  • Capsule endoscopy. For this test, you swallow a capsule containing a tiny camera that allows your doctor to see inside your GI tract.
  • Computerized tomography (CT) scan. A CT scan uses X-rays and computers to create images of the inside of the body.
  • Upper GI series (X-rays). An upper GI series may be done to look at the small intestine.


Treatment for Crohn's disease depends on:

  • where the disease is located in the GI tract
  • what problems you already have from the disease
  • what past treatments you have had for the disease

The goals of treatment are to:

  • decrease the inflammation
  • relieve symptoms such as abdominal pain, diarrhea, and rectal bleeding
  • correct nutritional problems

Treatment may include:

  • medicines
  • surgery
  • eating, diet, and nutrition


One or more of the following medicines may be used to treat Crohn's disease:

  • Anti-inflammation medicines may be used first to treat your Crohn's disease. These medicines help reduce inflammation in the intestine and relieve pain and diarrhea. Sometimes anti-inflammation medicines cause side effects, so you should talk with your health care provider about what to expect.
  • Corticosteroids also help lower inflammation. Steroids are similar to natural chemicals in the body. However, steroids are used only for a short time because long-term use can lead to serious side effects.
  • Immune system suppressors. Azathioprine and 6-mercaptopurine work by keeping your immune system from attacking harmless foreign substances. Immune system suppressors also cause side effects, so you should talk with your health care provider about what to expect.
  • Biological therapies. Biological therapies are medicines that are given by an injection in the vein, or an injection in the skin. There are currently five FDA-approved biological drugs that treat inflammation in Crohn's disease.
  • Antibiotics. Antibiotics are used to treat infectious complications of Crohn's disease, such as fistulas or abscesses.
  • Antidiarrheal medicines and fluid replacements. Diarrhea and abdominal cramps are often relieved when the inflammation improves, but more medicine may be needed. Antidiarrheal medicines include diphenoxylate, loperamide, and codeine. People with diarrhea should drink plenty of fluids to prevent dehydration—loss of fluids from the body. If diarrhea does not improve, the person should see the doctor promptly for possible treatment with fluids given through a small tube inserted into an arm vein.


As many as two-thirds to three-quarters of people with Crohn's disease will require surgery at some point during their lives.

While surgery does not cure Crohn's disease, it can conserve portions of your GI tract and return you to the best possible quality of life.

Surgery becomes necessary when medications can no longer control symptoms, or if you develop a fistula, fissure, or intestinal obstruction. Surgery often involves removal of the diseased segment of bowel (resection), and then the two ends of healthy bowel are joined together (anastomosis). While these procedures may cause your symptoms to disappear for years, Crohn's frequently recurs after surgery.

Sometimes you need to have more than one surgery because the disease returns next to where the intestine was removed. Because Crohn's disease can return after surgery, you can talk with your health care provider and other patients to get as much information as possible before having surgery.

Eating, Diet, and Nutrition

Your health care provider may start you on a special diet, so you get extra nutrition and calories. High-calorie liquid supplements are often used to give you the extra calories and right amount of vitamins and minerals to keep you healthy. During acute phases of the disease, you may need to receive intravenous nutrition to give the intestine a rest.

No foods are known to cause injury or inflammation to the intestine. But foods such as hot spices, alcohol, greasy foods, and milk products may make diarrhea and cramping worse. You should eat a healthy diet and avoid foods that make symptoms worse. Your health care provider may refer you to a dietitian to help you with meal planning.

Crohn's Disease and Stress

People with Crohn's disease sometimes feel more stress in their lives, which can make symptoms worse. Eating well, getting enough rest, and learning to relax may help you through stressful times. Support groups may help lower stress for people with Crohn's disease. Ask your health care provider for help finding support groups.

Even though you may need medicines and other treatments, you may feel well and be symptom-free for long periods of time. Most people with Crohn's disease are able to work and live full lives. Women with Crohn's disease can have successful pregnancies.

NIH Research

The National Institute of Diabetes and Digestive and Kidney Diseases Division of Digestive Diseases and Nutrition supports research into digestive conditions, including Crohn's disease. Researchers are working to better understand genes and Crohn's disease. They are also studying new medicines and ways to deliver medicines that might be more effective than current treatments.

Participants in clinical trials can play a more active role in their own health care, gain access to new research treatments before they are widely available, and help others by contributing to medical research. For information about current studies, visit

Read More "Crohn's Disease" Articles

Living with Crohn's Disease / What Is Crohn's Disease / Meeting the Challenge of Crohn's Disease

Winter 2016 Issue: Volume 10 Number 4 Page 4-5