Crohn's disease Cause and Treatments
January 07, 2007
What is Crohn's Disease?

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 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.

                                  
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SOURCE Crohn's Disease NIH Publication No. 03-3410 January 2003
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.
Most people are first treated
with drugs containing
mesalamine, a substance
that helps control
inflammation.