|
McKesson Clinical Reference Systems: Women's Health Advisor 2002.2
Illustration
Small Bowel Obstruction
What is a small bowel obstruction?
A small bowel obstruction is a blockage of the small
intestine.
The small bowel begins at the end of the stomach and ends
where the colon (large intestine) starts. In most adults,
the small bowel is about 21 feet long.
The bowels can become trapped inside the abdominal cavity in
scar tissue or outside the abdominal cavity in a hernia.
When blood flow to the blocked part of the bowel is cut off
and the bowel wall begins to die, it is said to be
strangulated. This can be life threatening but it occurs in
only one fourth to one third of cases of small bowel
obstruction.
How does it occur?
Adhesions are the major cause of small bowel obstruction.
Adhesions are bands of scar tissue that form after surgery.
The adhesions grow across sections of the bowel, trapping
portions. Other causes include:
- hernia, a weakness in the wall of the abdomen through
which the intestines protrude
- inflammatory bowel disease
- the intestine folding into itself, cutting off normal
flow of partly digested food and eventually cutting off
blood flow to the tissues
- a twisted or knotted bowel
- a narrowing of bowel that you were born with
- a lack of oxygen flow to the bowel, causing part of the
bowel to die
- cancer.
What are the symptoms?
The symptoms of a blocked small bowel include:
- cramplike pain in the abdomen
- a tender and enlarged abdomen
- vomiting
- slight fever
- failure to pass gas or stools
- lack of enough water in the body (dehydration), which can
cause flushed, dry skin; coated tongue; weakness; and
confusion.
How is it diagnosed?
Your health care provider will review your symptoms, take
your medical history, and examine you. He or she will ask
about previous surgeries, bowel blockages, and hernias.
Your provider may order the following tests:
- blood tests
- x-rays of the chest and abdomen
- x-rays of the bowel after a barium enema
- endoscopy or colonoscopy, which is examination of the
colon through a long, flexible tube.
How is it treated?
If your small bowel is partly blocked, the treatment may
include decreasing the pressure of bowel gas by passing a
tube through your nose to your stomach. Your health care
provider may prescribe antibiotics. You may need IV fluids
to replace lost fluids and to prevent further dehydration.
You will need surgery if your small bowel is completely
blocked. The decision to operate is based on the following:
- too many white blood cells, indicating infection
- strangulation, caused by not enough blood reaching the
affected area of the bowel
- worsening symptoms
- tenderness of your abdomen
- blood in your stool
- air under your diaphragm (the sheet of muscle that
separates your chest from your abdomen), which means
there is a hole in the wall of your bowel
- an infection in the lining of your abdomen.
If you need an operation, the surgeon will make a cut
through the wall of your abdomen and relieve the blockage.
The surgeon may remove a portion of bowel. Your health care
provider may prescribe antibiotics for infection.
How long will the effects last?
How long the effects last depends on what caused the
blockage and whether the bowel has been strangulated. It
is important to get up and walk as soon after surgery as is
reasonable. Walking helps get the bowel to start moving
again.
How can I help prevent small bowel obstruction?
You may have little control over preventing an obstruction.
Scar tissue may form in the abdomen from surgery, injury
(such as penetrating wounds or auto accidents), and
infections. Being active after any surgery or bowel injury
may help prevent adhesions. If you have a hernia in the
abdominal wall or groin, ask your health care provider if
repair would help prevent a bowel obstruction.
|