Crohn's Disease
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The digestive system.
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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.
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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.
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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.
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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.
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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.
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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 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.
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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.
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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.
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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.
- IVIg. Several studies have shown IVIg works well in
Crohns
- 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.
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