Crohn's disease is a chronic condition associated with inflammation and injury of the intestines. It typically begins in young adulthood, most often between 15 and 40 years of age.

No one knows for sure what triggers the intestinal inflammation. Many experts think that a virus or a bacterial infection might start the process and that the body's immune system malfunctions and stays active after the infection has cleared. Family members may share genes that make Crohn's disease or another similar inflammatory bowel disease, ulcerative colitis, more likely to develop if the right trigger occurs. Ten percent to 25 percent of people who have Crohn's disease have at least one relative with Crohn's disease or ulcerative colitis. The disease is not contagious, so there is no concern about spreading the disease from one person to another. Smoking is a risk factor for developing Crohn's disease, for having more active disease, and for responding less well to certain treatments.

Once Crohn's disease begins, it can cause intermittent, lifelong symptoms by inflaming the inside lining and deeper layers of the intestine wall. The irritated intestine lining can thicken or wear away in spots, which creates ulcers, or in cracks, which creates fissures. Inflammation also can allow an abscess (a pocket of pus) to develop. In between attacks of inflammation, the intestine attempts to heal by recoating itself with a new lining. When the inflammation has been severe, the intestine can lose its ability to distinguish the inside of one piece of intestine from the outside of another piece. As a result, it can mistakenly build a lining along the edges of an ulcer that has worn through the whole wall of the intestine, creating a fistula — an abnormal connection between one piece of the intestine and another. A fistula sometimes can form between the intestine and the skin surface, creating drainage of mucous to the skin.

The last portion of the small intestine (the end of the ileum, in the right lower abdomen) is especially prone to damage from Crohn's disease. However, ulcers and inflammation can occur in all areas of the digestive tract, from the mouth all the way to the rectum. A few other parts of the body, such as the eyes and joints, may become inflamed in people with Crohn's disease.

Some people have only occasional cramps, diarrhea or even constipation that is so mild that they do not seek medical attention. Occasionally, the disease does not cause any symptoms. However, most people who have Crohn's disease experience long stretches of time with no symptoms interrupted by bursts of symptoms, called an exacerbation, when inflammation returns. During an exacerbation, or during the initial appearance of Crohn's disease, you might experience the following symptoms:

It may require months for your doctor to diagnose Crohn's disease confidently. To confirm the diagnosis, your doctor will look for evidence of intestinal inflammation and to distinguish it from other causes of intestinal problems, such as infection or ulcerative colitis (a related disease that also causes intestinal inflammation.) If you have Crohn's disease, your symptoms and the results of tests will fit a pattern over time that is best explained by this condition.

Tests that can indicate inflammation and show evidence of Crohn's disease include:

Crohn's disease is a lifelong condition, but it is not continuously active so there can be long breaks in symptoms. Following a flare-up, symptoms can stay for weeks or months. Often these flare-ups are separated by months or years of good health with no symptoms.

There is no known way to prevent Crohn's disease but you can help the condition take less of a toll on your body by maintaining a well-balanced, nutritious diet. By storing up vitamins and nutrients even between episodes, you can decrease complications from malnutrition, such as weight loss or anemia. Your doctor also will monitor your blood tests for complications of poor nutrient absorption.

Crohn's disease can cause a higher risk of colon cancer, particularly if it affects a large portion of the colon or rectum. It is important to have the colon checked regularly for early signs of cancer or for changes that can precede a new cancer. If you have had Crohn's disease affecting the colon or rectum for eight years or more, it is time for you to start getting regular testing to screen for cancer. One good strategy is to have a colonoscopy exam every one to two years once you start regular testing.

Medications are very effective for improving the symptoms of Crohn's disease. Most of the medications that are used work by preventing inflammation in the intestines.

The medication that is commonly tried first is a group of anti-inflammatory drugs called aminosalicylates. These drugs are related chemically to aspirin, and they suppress inflammation in the intestine and in joints. They are given either by mouth (pills) or by rectum, as an enema. Some drugs in this group include sulfasalazine (Azulfidine), mesalamine (Asacol, Pentasa, Canasa, Rowasa) and olsalazine (Dipentum).

Certain antibiotic drugs, particularly metronidazole (Flagyl) and ciprofloxacin (Cipro), help by decreasing the bacterial growth in irritated areas of the bowel and may have a side benefit of decreasing inflammation. If symptoms are controlled only partially and infection has been excluded, antidiarrheal medications, such as loperamide (Lomotil) may be helpful.

Another approach is "bowel rest" in which limited or no nutrition is taken in by mouth and all nutritional needs are met by intravenous (IV) therapy or special oral formulas. However, this may not be well tolerated, and the intravenous line can become infected or form blood clots.

Other more powerful anti-inflammatory drugs may be helpful, but they have a side effect of suppressing your immune system so that you have an increased risk of infections. For this reason, they are less often used on a long-term basis. These drugs include prednisone (Deltasone, Prednisolone, Orasone) and methylprednisolone (Medrol, Solu-Medrol), budesonide (Entocort), azathioprine (Imuran), 6-mercaptopurine (Purinethol), cyclosporine (Neoral, Sandimmune) and methotrexate (Rheumatrex, Folex).

A new drug, infliximab (Remicade) has been used in recent years for severe Crohn's disease, particularly when a fistula has formed and does not respond to other treatment. This medication blocks the effect of tumor necrosis factor, a chemical that may be responsible for causing inflammation in the intestine. In general, surgery to remove a section of the bowel is recommended only if a person has bowel obstruction, persistent symptoms despite medical therapy, or a non-healing fistula. Up to 50 percent of people who have Crohn's disease will end up having at least one operation during the course of their disease.

Crohn's disease can affect people very differently. Many people have only mild symptoms and do not require continuous treatment with medication. Others require multiple medications and develop complications. Crohn's disease improves with treatment and is not a fatal illness, but it cannot be cured. Crohn's requires people to pay special attention to their health needs and to seek frequent medical care, but it does not prevent most people from having normal jobs and productive family lives. As is the case for any chronic illness, it can be helpful for a newly diagnosed person to seek advice from a support group of other people with the disease.

Additional Info

Crohn's and Colitis Foundation of America
386 Park Ave. South
17th Floor
New York, NY 10016
Toll-Free: (800) 932-2423
Fax: (212) 779-4098