What is a Barium Enema?
A Barium Enema, also called a lower
gastrointestinal series, is a medical procedure used to examine and
diagnose problems with the human large intestines. An X-ray
examination of the large intestines, pictures are taken after rectal
instillation of barium sulfate.
How the test is performed
This test may be done in a hospital or clinic radiology department.
The patient lies on the X-ray table and a preliminary X-ray is
taken. The patient is then asked to lie on the side while a well
lubricated enema tube is inserted gently into the rectum. The
barium, a radiopaque (shows up on X-ray) contrast medium, is then
allowed to flow into the colon. A small balloon at the tip of the
enema tube may be inflated to help keep the barium inside. The flow
of the barium is monitored by the health care provider on an X-ray
fluoroscope screen (like a TV monitor). Air may be puffed into the
colon to distend it and provide better images.
The patient is usually asked to move to different positions and the
table is slightly tipped to get different views.
If a double or air - contrast examination is being done, the enema
tube will be reinserted gently and a small amount of air will be
gently introduced into the colon, and more X-ray pictures are taken.
If there is a suspected bowel perforation, water-soluble contrast is
used instead of barium. The study is otherwise very similar,
although the images are not quite as good. (The concern with
existing perforation is that contrast will leak from the bowel to
the peritoneal cavity, and water-soluble material is less irritating
Thorough cleaning of the large intestine is necessary for accurate
pictures. Test preparations include a clear liquid diet, drinking a
bottle of magnesium citrate (a laxative), and warm water enemas to
clear out any stool particles.
Why the test is performed
The test is used to detect colon cancer. The barium enema may also
be used to diagnose and evaluate the extent of inflammatory bowel
diseases such as Crohn's disease.
Barium study is usually used to diagnosis disease. However, in
certain cases, barium enema is used to treat intussusception.
Barium should fill the colon uniformly and show normal bowel
contour, patency (should be freely open), and position.
What abnormal results mean
Abnormal findings may include cancer, diverticulitis (small pouches
formed on the colon wall that can become inflamed), polyps (a tumor,
usually noncancerous, that grows on the mucous membrane),
inflammation of the inner lining of the intestine (ulcerative
colitis), and irritable colon. An acute appendicitis or twisted loop
of the bowel may also be seen.
Additional conditions under which the test may be performed:
* annular pancreas
* CMV gastroenteritis/colitis
* colorectal polyps
* Hirschsprung's disease
* intestinal obstruction
* intussusception (children)
* pyloric stenosis
What the risks are
There is low radiation exposure. X-rays are monitored and regulated
to provide the minimum amount of radiation exposure needed to
produce the image. Most experts feel that the risk is low compared
with the benefits. Pregnant women and children are more sensitive to
the risks of the X-ray.
A more serious risk is a bowel perforation, which is very rare.
CT scans and ultrasounds are now the tests of choice for the initial
evaluation of abdominal masses.