Crohn's Disease

Crohn’s disease causes inflammation and irritation in the digestive tract. It can cause pain, diarrhea, weight loss, and malnutrition. Crohn’s disease is manageable with medicines and/or surgery.

Crohn's Disease Overview

Reviewed: May 19, 2014
Updated: 

Crohn’s disease is a disease that causes inflammation (swelling) and irritation of the digestive or gastrointestinal tract. Crohn's disease can affect any part of the digestive tract from the mouth to the anus, but the most commonly affected section is the lower part of the small intestine called the ileum.

Crohn's disease is 1 of 2 main forms of diseases that are called inflammatory bowel disease (IBD). (The other is ulcerative colitis.) The inflammation of the lining of the digestive tract can lead to abdominal pain, severe diarrhea, fatigue, weight loss, and malnutrition. The inflammation caused by Crohn's disease often spreads deep into the layers of affected bowel tissue. Chronic inflammation can lead to the development of scar tissue in the intestine, which narrows the passage in the digestive tract and slows the movement of food and stool through the intestine. Crohn's disease can be both painful and debilitating, and sometimes may lead to life-threatening complications.

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 most commonly starts between the ages of 13 and 30.

There is no known cure for Crohn's disease, but therapies can greatly reduce its signs and symptoms and even bring about long-term remission. With treatment, many people with Crohn's disease are able to function well.

Crohn's Disease Symptoms

Signs and symptoms of Crohn's disease can range from mild to severe. They usually develop gradually, but sometimes will come on suddenly, without warning. You may also have periods of time when you have no signs or symptoms (remission).

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

  • abdominal pain—often in the lower right area of the abdomen
  • diarrhea
  • blood in the stool
  • drainage near the anus
  • reduced appetite and weight loss
  • fever
  • fatigue
  • mouth sores

People with severe Crohn's disease may also experience inflammation of skin, eyes and joints or inflammation of the liver or bile ducts.

Children with Crohn’s disease may experience delayed growth or sexual development.

Crohn's Disease Causes

The exact cause of Crohn's disease remains unknown. Previously, diet and stress were suspected, but now doctors know that these factors may aggravate but do not cause Crohn's disease. A number of factors, such as heredity and an immune system that is not functioning correctly, likely play a role in its development.

Immune system. It is possible that a virus or bacterium may trigger Crohn's disease. When your immune system tries to fight off the invading microorganism, an abnormal immune response causes the immune system to attack the cells in the digestive tract, too.

Heredity. Crohn's disease is more common in people who have family members with the disease, so genes may play a role in making people more susceptible. However, most people with Crohn's disease do not have a family history of the disease.

Risk factors for Crohn's disease include:

  • Age. Crohn's disease can occur at any age, but you are likely to develop the condition when you are young. Most people who develop Crohn's disease are diagnosed before 30 years old.
  • Ethnicity. Although Crohn's disease can affect any ethnic group, Caucasians and people of Eastern European (Ashkenazi) Jewish descent have the highest risk.
  • Family history. People who have a close relative, such as a parent, sibling .or child, with the disease are more likely to develop Crohn’s.
  • Cigarette smoking. Cigarette smoking is the most important controllable risk factor for developing Crohn's disease. Smoking also leads to more severe disease and a greater risk of having surgery.
  • Nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs do not cause Crohn's disease, but they can lead to inflammation of the digestive tract that makes Crohn's disease worse. Examples of common NSAIDs are ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve, Anaprox), and diclofenac sodium (Voltaren, Solaraze).
  • Where you live. People who live in an urban area or in an industrialized country are more likely to develop Crohn's disease. This suggests that environmental factors, including a diet high in fat or refined foods, play a role in Crohn's disease. People living in northern climates also seem to be at greater risk.

Crohn's Disease Diagnosis

Your doctor will likely diagnose Crohn's disease only after ruling out other possible causes for your signs and symptoms. There is no single test to diagnose Crohn's disease.

Your doctor will likely perform a physical exam and use a combination of endoscopy with biopsies and radiological testing to confirm a diagnosis of Crohn's disease. You may have one or more of the following tests and procedures:

  • Blood tests for anemia or infection. Your doctor may suggest blood tests to check for anemia — a condition in which there aren't enough red blood cells to carry adequate oxygen to your tissues — or to check for signs of infection. Expert guidelines do not currently recommend antibody or genetic testing for Crohn's disease.
  • Fecal occult blood test. You may need to provide a stool sample so that your doctor can test for hidden blood in your stool. This test is commonly used to rule out other causes of gastrointestinal disease.
  • Colonoscopy. Colonoscopy is the most common test used in the diagnosis of Crohn’s disease. This test allows your doctor to view your entire colon using a thin, flexible, lighted tube with an attached camera. During the procedure, your doctor can also take small samples of tissue (biopsy) for laboratory analysis, which may help confirm a diagnosis. Clusters of inflammatory cells called granulomas, if present, help confirm the diagnosis of Crohn's.
  • Flexible sigmoidoscopy. In this procedure, your doctor uses a slender, flexible, lighted tube to examine the sigmoid, the last section of your colon.
  • Computerized tomography (CT). You may have a CT scan — a special X-ray technique that provides more detail than a standard X-ray does. This test looks at the entire bowel as well as at tissues outside the bowel.
  • Magnetic resonance imaging (MRI). An MRI scanner uses a magnetic field and radio waves to create detailed images of organs and tissues. MRI is particularly useful for evaluating a fistula around the anal area (pelvic MRI) or the small intestine (MR enterography).
  • Capsule endoscopy. For this test, you swallow a capsule that has a camera in it. The camera takes pictures, which are transmitted to a computer you wear on your belt. The images are then downloaded, displayed on a monitor and checked for signs of Crohn's disease. The camera exits your body painlessly in your stool. You may still need endoscopy with biopsy to confirm the diagnosis of Crohn's disease.
  • Double-balloon endoscopy. For this test, a longer scope is used to look further into the small bowel where standard endoscopes don't reach. This technique is useful when capsule endoscopy shows abnormalities, but the diagnosis is still in question.
  • Small bowel imaging. This test looks at the part of the small bowel that can't be seen by colonoscopy. After you drink a liquid containing barium, doctors take X-ray, CT or MRI images of your small intestine.

Living With Crohn's Disease

Crohn's disease may lead to one or more of the following complications:

  • Inflammation. Inflammation may be confined to the bowel wall, which can lead to scarring and narrowing (stenosis), or may spread through the bowel wall (fistula).
  • Bowel obstruction. Crohn's disease affects the thickness of the intestinal wall. Over time, parts of the bowel can thicken and narrow, which may block the flow of digestive contents. You may require surgery to remove the diseased portion of your bowel.
  • Ulcers. Chronic inflammation can lead to open sores (ulcers) anywhere in your digestive tract, including your mouth and anus, and in the genital area (perineum).
  • Fistulas. Sometimes ulcers can extend completely through the intestinal wall, creating a fistula — an abnormal connection between different body parts. Fistulas can develop between your intestine and skin or between your intestine and another organ. Fistulas near or around the anal area (perianal) are the most common kind.
  • Anal fissure. This is a small tear in the tissue that lines the anus or in the skin around the anus where infections can occur. It is often associated with painful bowel movements and may lead to a perianal fistula.
  • Malnutrition. Diarrhea, abdominal pain, and cramping may make it difficult for you to eat or for your intestine to absorb enough nutrients to keep you nourished. It's also common to develop anemia due to low iron or vitamin B-12 caused by the disease.
  • Colon cancer. Having Crohn's disease that affects your colon increases your risk of colon cancer. General colon cancer screening guidelines for people without Crohn's disease call for a colonoscopy every 10 years beginning at age 50. Ask your doctor whether you need to have this test done sooner and more frequently.
  • Other health problems. Crohn's disease can cause problems in other parts of the body. Among these problems are anemia, osteoporosis, and gallbladder or liver disease.

Crohn's disease can take an emotional toll on you. If signs and symptoms are severe, your life may revolve around a constant need to use the toilet. Even if your symptoms are mild, gas, and abdominal pain can make it difficult to be out in public. All of these factors can alter your life and may lead to depression. Here are some things you can do:

  • Be informed. One of the best ways to be more in control is to find out as much as possible about Crohn's disease so you can make informed decisions about your care and treatment plans.
  • Join a support group. Support groups can provide valuable information about your condition, as well as emotional support. Group members frequently know about the latest medical treatments or integrative therapies. You may also find it reassuring to be among others with Crohn's disease.
  • Talk to a therapist. Some people find it helpful to consult a mental health professional who is familiar with inflammatory bowel disease and the emotional difficulties it can cause.

Crohn’s disease can be difficult to live with, but most people with Crohn’s disease are able to work, raise families, and live full lives.

Crohn's Disease Treatments

The goals of treatment of Crohn’s disease are to decrease the inflammation; relieve symptoms such as abdominal pain, diarrhea, and rectal bleeding; and correct nutritional problems. Treatment for Crohn’s disease depends on where the disease is located in the digestive tract, what problems you already have from the disease, and what treatments you have already tried for the disease. Treatment may include combinations of medicines, surgery, and diet and nutrition support. There is currently no cure for Crohn’s disease, and there is no single treatment regimen that works for everyone. Doctors use 1 of 2 approaches to treatment — either "step-up," which starts with milder drugs first, or "top-down," which gives people stronger drugs earlier in the treatment process. You and your doctor will decide which approach is right for you.

The following medicines may be used to treat Crohn’s disease.

  • Anti-inflammatory medicines. These medicines help decrease inflammation in the intestine and relieve pain and diarrhea associated with the disease.
  • Steroids. These drugs also help decrease inflammation. Steroids are similar to natural chemicals in the body, but they can only be used for a short time because long-term use can lead to serious side effects.
  • Immune system suppressors. Azathioprine (Imuran, Azasan) and 6-mercaptopurine (Purinethol) work by keeping your immune system from attacking harmless foreign substances. Immune system suppressors can make you more susceptible to infections, so 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, infliximab (Remicade), or an injection in the skin, adalimumab (Humira). Your health care provider may recommend these medicines if others are not helping to decrease inflammation or if you have fistulas with abscesses.
  • Anti-infective agents. Anti-infectives are used to treat the overgrowth of potentially infectious organisms in the small intestine caused by stricture, fistulas, or surgery. For this common problem, the doctor may prescribe one or more of the following antibiotics: ampicillin, sulfonamides such as sulfamethoxazole/trimethoprim (Sulfatrim, Bactrim, Septra, others), cephalosporins such as ciprofloxacin (Cipro), or metronidazole (Flagyl).
  • Anti-diarrheal medicines and fluid replacements. Diarrhea and abdominal cramps are often relieved when the inflammation improves, but more medicine may be needed. Anti-diarrheal medicines include diphenoxylate (Lomotil), loperamide (Imodium), 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.

Some people with Crohn’s disease need surgery if medicines are no longer working to control blockage, fistulas, abscesses, and bleeding. One or more of the following surgeries may be needed:

  • Intestinal resection. The surgeon removes the diseased section of intestine and puts the ends of the intestine back together.
  • Proctocolectomy. Proctocolectomy is surgery to remove the rectum and part or all of the colon.
  • Ileostomy. Ileostomy is an operation to create an opening—called a stoma—for the stool to exit the body when the ends of the intestine cannot be put back together.

Crohn's Disease Other Treatments


Crohn's Disease Prognosis