Crohn's Disease
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The digestive system. |
Crohn's disease causes inflammation in the small intestine. Crohn's disease usually occurs in the lower part of the small
intestine, called the ileum, but it can affect any part of the digestive tract, from the mouth to the anus. The inflammation
extends deep into the lining of the affected organ. The inflammation can cause pain and can make the intestines empty frequently,
resulting in diarrhea.
Crohn's disease is an inflammatory bowel disease (IBD), the general name for diseases that cause inflammation in the intestines.
Crohn's disease can be difficult to diagnose because its symptoms are similar to other intestinal disorders such as irritable
bowel syndrome and to another type of IBD called ulcerative colitis. Ulcerative colitis causes inflammation and ulcers in
the top layer of the lining of the large intestine.
Crohn's disease affects men and women equally and seems to run in some families. About 20 percent of people with Crohn's
disease have a blood relative with some form of IBD, most often a brother or sister and sometimes a parent or child.
Crohn's disease may also be called ileitis or enteritis.
What causes Crohn's disease?
Theories about what causes Crohn's disease abound, but none has been proven. The most popular theory is that the body's
immune system reacts to a virus or a bacterium by causing ongoing inflammation in the intestine.
People with Crohn's disease tend to have abnormalities of the immune system, but doctors do not know whether these abnormalities
are a cause or result of the disease. Crohn's disease is not caused by emotional distress.
What are the symptoms?
The most common symptoms of Crohn's disease are abdominal pain, often in the lower right area, and diarrhea. Rectal bleeding,
weight loss, and fever may also occur. Bleeding may be serious and persistent, leading to anemia. Children with Crohn's disease
may suffer delayed development and stunted growth.
How is Crohn's disease diagnosed?
A thorough physical exam and a series of tests may be required to diagnose Crohn's disease.
Blood tests may be done to check for anemia, which could indicate bleeding in the intestines. Blood tests may also uncover
a high white blood cell count, which is a sign of inflammation somewhere in the body. By testing a stool sample, the doctor
can tell if there is bleeding or infection in the intestines.
The doctor may do an upper gastrointestinal (GI) series to look at the small intestine. For this test, the patient drinks
barium, a chalky solution that coats the lining of the small intestine, before x rays are taken. The barium shows up white
on x-ray film, revealing inflammation or other abnormalities in the intestine.
The doctor may also do a colonoscopy. For this test, the doctor inserts an endoscope—a long, flexible, lighted tube
linked to a computer and TV monitor—into the anus to see the inside of the large intestine. The doctor will be able
to see any inflammation or bleeding. During the exam, the doctor may do a biopsy, which involves taking a sample of tissue
from the lining of the intestine to view with a microscope.
If these tests show Crohn's disease, more x rays of both the upper and lower digestive tract may be necessary to see how
much is affected by the disease.
What are the complications of Crohn's disease?
The most common complication is blockage of the intestine. Blockage occurs because the disease tends to thicken the intestinal
wall with swelling and scar tissue, narrowing the passage. Crohn's disease may also cause sores, or ulcers, that tunnel through
the affected area into surrounding tissues such as the bladder, vagina, or skin. The areas around the anus and rectum are
often involved. The tunnels, called fistulas, are a common complication and often become infected. Sometimes fistulas can
be treated with medicine, but in some cases they may require surgery.
Nutritional complications are common in Crohn's disease. Deficiencies of proteins, calories, and vitamins are well documented
in Crohn's disease. These deficiencies may be caused by inadequate dietary intake, intestinal loss of protein, or poor absorption
(malabsorption).
Other complications associated with Crohn's disease include arthritis, skin problems, inflammation in the eyes or mouth,
kidney stones, gallstones, or other diseases of the liver and biliary system. Some of these problems resolve during treatment
for disease in the digestive system, but some must be treated separately.
What is the treatment for Crohn's disease?
Treatment for Crohn's disease depends on the location and severity of disease, complications, and response to previous
treatment. The goals of treatment are to control inflammation, correct nutritional deficiencies, and relieve symptoms like
abdominal pain, diarrhea, and rectal bleeding. Treatment may include drugs, nutrition supplements, surgery, or a combination
of these options. At this time, treatment can help control the disease, but there is no cure.
Some people have long periods of remission, sometimes years, when they are free of symptoms. However, the disease usually
recurs at various times over a person's lifetime. This changing pattern of the disease means one cannot always tell when a
treatment has helped. Predicting when a remission may occur or when symptoms will return is not possible.
Someone with Crohn's disease may need medical care for a long time, with regular doctor visits to monitor the condition.
Drug Therapy
Most people are first treated with drugs containing mesalamine, a substance that helps control inflammation. Sulfasalazine
is the most commonly used of these drugs. Patients who do not benefit from it or who cannot tolerate it may be put on other
mesalamine-containing drugs, generally known as 5-ASA agents, such as Asacol, Dipentum, or Pentasa. Possible side effects
of mesalamine preparations include nausea, vomiting, heartburn, diarrhea, and headache.
Some patients take corticosteroids to control inflammation. These drugs are the most effective for active Crohn's disease,
but they can cause serious side effects, including greater susceptibility to infection.
Drugs that suppress the immune system are also used to treat Crohn's disease. Most commonly prescribed are 6-mercaptopurine
and a related drug, azathioprine. Immunosuppressive agents work by blocking the immune reaction that contributes to inflammation.
These drugs may cause side effects like nausea, vomiting, and diarrhea and may lower a person's resistance to infection. When
patients are treated with a combination of corticosteroids and immunosuppressive drugs, the dose of corticosteriods can eventually
be lowered. Some studies suggest that immunosuppressive drugs may enhance the effectiveness of corticosteroids.
The U.S. Food and Drug Administration has approved the drug infliximab (brand name, Remicade) for the treatment of moderate
to severe Crohn's disease that does not respond to standard therapies (mesalamine substances, corticosteroids, immunosuppressive
agents) and for the treatment of open, draining fistulas. Infliximab, the first treatment approved specifically for Crohn's
disease, is an anti-tumor necrosis factor (TNF) substance. TNF is a protein produced by the immune system that may cause the
inflammation associated with Crohn's disease. Anti-TNF removes TNF from the bloodstream before it reaches the intestines,
thereby preventing inflammation. Investigators will continue to study patients taking infliximab to determine its long-term
safety and efficacy.
Antibiotics are used to treat bacterial overgrowth in the small intestine caused by stricture, fistulas, or prior surgery.
For this common problem, the doctor may prescribe one or more of the following antibiotics: ampicillin, sulfonamide, cephalosporin,
tetracycline, or metronidazole.
Diarrhea and crampy abdominal pain are often relieved when the inflammation subsides, but additional medication may also
be necessary. Several antidiarrheal agents could be used, including diphenoxylate, loperamide, and codeine. Patients who are
dehydrated because of diarrhea will be treated with fluids and electrolytes.
Nutrition Supplementation
The doctor may recommend nutritional supplements, especially for children whose growth has been slowed. Special high-calorie
liquid formulas are sometimes used for this purpose. A small number of patients may need periods of feeding by vein. This
can help patients who need extra nutrition temporarily, those whose intestines need to rest, or those whose intestines cannot
absorb enough nutrition from food.
Surgery
Surgery to remove part of the intestine can help Crohn's disease but cannot cure it. The inflammation tends to return next
to the area of intestine that has been removed. Many Crohn's disease patients require surgery, either to relieve symptoms
that do not respond to medical therapy or to correct complications such as blockage, perforation, abscess, or bleeding in
the intestine.
Some people who have Crohn's disease in the large intestine need to have their entire colon removed in an operation called
colectomy. A small opening is made in the front of the abdominal wall, and the tip of the ileum is brought to the skin's surface.
This opening, called a stoma, is where waste exits the body. The stoma is about the size of a quarter and is usually located
in the right lower part of the abdomen near the beltline. A pouch is worn over the opening to collect waste, and the patient
empties the pouch as needed. The majority of colectomy patients go on to live normal, active lives.
Sometimes only the diseased section of intestine is removed and no stoma is needed. In this operation, the intestine is
cut above and below the diseased area and reconnected.
Because Crohn's disease often recurs after surgery, people considering it should carefully weigh its benefits and risks
compared with other treatments. Surgery may not be appropriate for everyone. People faced with this decision should get as
much information as possible from doctors, nurses who work with colon surgery patients (enterostomal therapists), and other
patients. Patient advocacy organizations can suggest support groups and other information resources. (See For More Information
below for the names of such organizations.)
People with Crohn's disease may feel well and be free of symptoms for substantial spans of time when their disease is not
active. Despite the need to take medication for long periods of time and occasional hospitalizations, most people with Crohn's
disease are able to hold jobs, raise families, and function successfully at home and in society.
Can diet control Crohn's disease?
No special diet has been proven effective for preventing or treating this disease. Some people find their symptoms are
made worse by milk, alcohol, hot spices, or fiber. People are encouraged to follow a nutritious diet and avoid any foods that
seem to worsen symptoms. But there are no consistent rules.
People should take vitamin supplements only on their doctor's advice.
Is pregnancy safe for women with Crohn's disease?
Research has shown that the course of pregnancy and delivery is usually not impaired in women with Crohn's disease. Even
so, women with Crohn's disease should discuss the matter with their doctors before pregnancy. Most children born to women
with Crohn's disease are unaffected. Children who do get the disease are sometimes more severely affected than adults, with
slowed growth and delayed sexual development in some cases.
Hope Through Research
Researchers continue to look for more effective treatments. Examples of investigational treatments include
- Anti-TNF. Research has shown that cells affected by Crohn's disease contain a cytokine, a protein produced by the
immune system, called tumor necrosis factor (TNF). TNF may be responsible for the inflammation of Crohn's disease. Anti-TNF
is a substance that finds TNF in the bloodstream, binds to it, and removes it before it can reach the intestines and cause
inflammation. In studies, anti-TNF seems particularly helpful in closing fistulas.
- Interleukin 10. Interleukin 10 (IL-10) is a cytokine that suppresses inflammation. Researchers are now studying
the effectiveness of synthetic IL-10 in treating Crohn's disease.
- Antibiotics. Antibiotics are now used to treat the bacterial infections that often accompany Crohn's disease, but
some research suggests that they might also be useful as a primary treatment for active Crohn's disease.
- Budesonide. Researchers recently identified a new corticosteroid called budesonide that appears to be as effective
as other corticosteroids but causes fewer side effects.
- Methotrexate and cyclosporine. These are immunosuppressive drugs that may be useful in treating Crohn's disease.
One potential benefit of methotrexate and cyclosporine is that they appear to work faster than traditional immunosuppressive
drugs.
- Natalizumab. Natalizumab is an experimental drug that reduces symptoms and improves the quality of life when tested
in people with Crohn's disease. The drug decreases inflammation by binding to immune cells and preventing them from leaving
the bloodstream and reaching the areas of inflammation.
- Zinc. Free radicals—molecules produced during fat metabolism, stress, and infection, among other things—may
contribute to inflammation in Crohn's disease. Free radicals sometimes cause cell damage when they interact with other molecules
in the body. The mineral zinc removes free radicals from the bloodstream. Studies are under way to determine whether zinc
supplementation might reduce inflammation.
For More Information
Crohn's & Colitis Foundation of America, Inc.
386 Park Avenue South, 17th Floor
New York, NY 10016–8804
Phone:
1–800–932–2423 or 212–685–3440
Email: info@ccfa.org
Internet: www.ccfa.org
Pediatric Crohn's & Colitis Association, Inc.
P.O. Box 188
Newton, MA 02468
Phone: 617–489–5854
Email: questions@pcca.hypermart.net
Internet: http://pcca.hypermart.net
Reach Out for Youth with Ileitis and Colitis, Inc.
15 Chemung Place
Jericho, NY 11753
Phone: 516–822–8010
United Ostomy Association, Inc.
19772 MacArthur Blvd.
#200
Irvine, CA 92612–2405
Phone: 1–800–826–0826
or 949–660–8624
Fax: 949–660–9262
Email: uoa@deltanet.com
Internet: www.uoa.org
The U.S. Government does not endorse or favor any specific commercial product or company. Trade, proprietary, or company
names appearing in this document are used only because they are considered necessary in the context of the information provided.
If a product is not mentioned, this does not mean or imply that the product is unsatisfactory.
National Digestive Diseases Information Clearinghouse
2 Information Way
Bethesda, MD 20892–3570
Email: nddic@info.niddk.nih.gov
The National Digestive Diseases Information Clearinghouse (NDDIC) is a service of the National Institute of Diabetes and
Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health under the U.S. Department of
Health and Human Services. Established in 1980, the Clearinghouse provides information about digestive diseases to people
with digestive disorders and to their families, health care professionals, and the public. The NDDIC answers inquiries, develops
and distributes publications, and works closely with professional and patient organizations and Government agencies to coordinate
resources about digestive diseases.
Publications produced by the Clearinghouse are carefully reviewed by both NIDDK scientists and outside experts.
This publication is not copyrighted. The Clearinghouse encourages users of this fact sheet to duplicate and distribute
as many copies as desired.
NIH Publication No. 03–3410
January 2003
http://digestive.niddk.nih.gov/ddiseases/pubs/crohns/
