Causes, incidence, and risk factors

The exact cause of Crohn's disease is unknown. It is an autoimmune disorder. An autoimmune disorder is a condition that occurs when your body's immune system mistakenly attacks and destroys healthy body tissue.

People with Crohn's disease have ongoing (chronic) inflammation of the gastrointestinal tract (GI tract). Crohn's disease may involve the small intestine, the large intestine, the rectum, or the mouth. The inflammation causes the intestinal wall to become thick.

There are different types of Crohn's disease. The type depends on what part of your body is affected.

The following seem to play a role in Crohn's disease:

• Your genes

• Environmental factors

• The body over-reacts to normal bacteria in the intestines

Crohn's disease may occur at any age. It usually occurs in people between ages 15 - 35.

You are more likely to get this disease if you:

• Have a family history of Crohn's disease

• Are Jewish

• Smoke

Symptoms

Symptoms depend on what part of the gastrointestinal tract is affected. Symptoms range from mild to severe, and can come and go with periods of flare-ups.

The main symptoms of Crohn's disease are:

• Crampy abdominal (belly area) pain

• Fever

• Fatigue

• Loss of appetite

• Pain with passing stool (tenesmus)

• Persistent, watery diarrhea

• Weight loss

Other symptoms may include:

• Constipation

• Eye inflammation

• Fistulas (usually around the rectal area, may cause draining of pus, mucus, or stools)

• Joint pain and swelling

• Mouth ulcers

• Rectal bleeding and bloody stools

• Skin lumps or sores (ulcers)

• Swollen gums

Signs and tests

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

Tests to diagnose Crohn's disease include:

• Barium enema or upper GI series

• Colonoscopy or sigmoidoscopy

• Computed tomography (CT scan) of the abdomen

• Endoscopy, including capsule endoscopy

• Magnetic resonance imaging (MRI) of the abdomen

• Enteroscopy

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:

• Albumin

• C-reactive protein

• Erythrocyte sedimentation rate

• Fecal fat

• Hemoglobin

• Liver function tests

• White blood cell count

Treatment

DIET AND NUTRITION

You should eat a well-balanced, healthy diet. It is important to get enough calories, protein, and essential nutrients from a variety of food groups.

No specific diet has been shown to make Crohn's symptoms better or worse. Specific food problems may vary from person to person.

However, certain types of foods can make diarrhea and gas worse. To help ease symptoms, try:

• Eating small amounts of food throughout the day.

• Drinking lots of water (drink small amounts often throughout the day).

• Avoiding high-fiber foods (bran, beans, nuts, seeds, and popcorn).

• Avoiding fatty, greasy or fried foods and sauces (butter, margarine, and heavy cream).

• Limiting dairy products if you have problems digesting dairy fats. Try low-lactose cheeses, such as Swiss and cheddar, and an enzyme product, such as Lactaid, to help break down lactose.

• Avoiding foods that you know cause gas, such as beans.

Ask your doctor about extra vitamins and minerals you may need:

• Iron supplements (if you are anemic)

• Calcium and vitamin D supplements to help keep your bones strong

• Vitamin B12 to prevent anemia

STRESS

You may feel worried, embarrassed, or even sad and depressed about having a bowel accident. Other stressful events in your life, such as moving, a job loss, or the loss of a loved one can cause digestive problems.

Ask your doctor or nurse for tips on how to manage your stress.

MEDICATIONS

You can take medication to treat very bad diarrhea. Loperamide (Imodium) can be bought without a prescription. Always talk to your doctor or nurse before using these drugs.

Other medicines to help with symptoms include:

• Fiber supplements may help your symptoms. You can buy psyllium powder (Metamucil) or methylcellulose (Citrucel) without a prescription. Ask your doctor about these products.

• Always talk to your doctor before using any laxative medicines.

• You may use acetaminophen (Tylenol) for mild pain.

• Drugs such as aspirin, ibuprofen (Advil, Motrin), or naproxen (Aleve, Naprosyn) may make your symptoms worse.

Your doctor may also give you a prescription for stronger pain medicines.

Medicines that may be prescribed include:

• Aminosalicylates (5-ASAs) are medicines that help control mild to moderate symptoms. Some forms of the drug are taken by mouth; others must be given rectally.

• Corticosteroids (prednisone and methylprednisolone) are used to treat moderate to severe Crohn's disease. They may be taken by mouth or inserted into the rectum.

• Medicines such as azathioprine or 6-mercaptopurine quiet the immune system's reaction.

• Antibiotics may be prescribed for abscesses or fistulas.

• Biologic therapy is used to treat patients with severe Crohn's disease that does not respond to any other types of medication. Medicines in this group include Infliximab (Remicade) and adalimumab (Humira), certolizumab (Cimzia), and natalizumab (Tysabri).

SURGERY

If medicines do not work, a type of surgery called bowel resection may be needed to remove a damaged or diseased part of the intestine or to drain an abscess. However, removing the diseased portion of the intestine does not cure the condition.

Patients who have Crohn's disease that does not respond to medications may need surgery, especially when there are complications such as:

• Bleeding (hemorrhage)

• Failure to grow (in children)

• Fistulas (abnormal connections between the intestines and another area of the body)

• Infections (abscesses)

• Narrowing (strictures) of the intestine

Some patients may need surgery to remove the entire large intestine (colon), with or without the rectum.

For information on what to expect after you are in the hospital for Crohn's disease, see: Crohn's disease - coming home from the hospital

See also:

• Ileostomy

• Large bowel resection

• Small bowel resection

• Total abdominal colectomy

• Total proctocolectomy with ileostomy

Support Groups

The Crohn's and Colitis Foundation of America offers support groups throughout the United States. See http://www.ccfa.org/chapters/

Expectations (prognosis)

There is no cure for Crohn's disease. The condition is marked by periods of improvement followed by flare-ups of symptoms.

It is very important to stay on medications long-term to try to keep the disease symptoms from returning. If you stop or change your medications for any reason, let your doctor know right away.

You have a higher risk for small bowel and colon cancer if you have Crohn's disease.

Complications

• Abscess

• Bowel obstructions

• Complications of corticosteroid therapy, such as thinning of the bones

• Erythema nodosum

• Fistulas in the following areas:

  • Bladder

  • Skin

  • Vagina

• Impaired growth and sexual development in children

• Inflammation of the joints

• Lesions in the eye

• Nutritional deficiency (particularly vitamin B12 deficiency)

• Pyoderma gangrenosum

Calling your health care provider

Call for an appointment with your health care provider if:

• You have very bad abdominal pain

• You cannot control your diarrhea with diet changes and drugs

• You have lost weight, or a child is not gaining weight

• You have rectal bleeding, drainage, or sores

• You have a fever that lasts for more than 2 or 3 days, or a fever higher than 100.4°F without an illness

• You have nausea and vomiting that lasts for more than a day

• You have skin sores or lesions that do not heal

• You have joint pain that prevents you from doing your everyday activities

• You have side effects from any drugs prescribed for your condition