A-Z Health Guide from WebMD: Medical Tests
Barium Enema
Test Overview
A barium enema, or lower gastrointestinal (GI) examination, is an
X-ray examination of the
large
intestine
(colon and rectum). The test is used to help diagnose diseases
and other problems that affect the large intestine. To make the intestine
visible on an X-ray picture, the colon is filled with a
contrast material containing barium. This is done by
pouring the contrast material through a tube inserted into the anus. The barium
blocks X-rays, causing the barium-filled colon to show up clearly on the X-ray
picture.
There are two types of barium enemas.
- In a
single-contrast study
, the colon is filled with
barium, which outlines the intestine and reveals large
abnormalities.
- In a double-contrast or
air-contrast study
, the colon is first filled with
barium and then the barium is drained out, leaving only a thin layer of barium
on the wall of the colon. The colon is then filled with air. This provides a
detailed view of the inner surface of the colon, making it easier to see
colon polyps,
colorectal cancer, or inflammation.
In some cases, the single-contrast study may be preferred for
specific medical reasons or for older people who may not be able to tolerate
the time-consuming and somewhat more uncomfortable double-contrast study.
However, if the results are not clear or there is a strong suspicion of
colorectal cancer, a double-contrast study may also be done.
Why It Is Done
A barium enema is done to:
- Screen for colon polyps or colon cancer. Most
medical experts recommend colon cancer screening
beginning at age 50 for people who do not have an increased risk of colon
cancer. Earlier screening is recommended for people who have an increased risk
of colon cancer, such as those with a family history of colon
cancer.
- Identify inflammation of the intestinal wall that occurs in
inflammatory bowel diseases, such as
ulcerative colitis or
Crohn's disease. A barium enema also may be used to
monitor the progress of these diseases.
- Detect problems with the
structure of the large intestine, such as narrowed areas (strictures) or
pockets or sacs (diverticula) in the intestinal
wall.
- Help correct a condition called ileocolic
intussusception
, in which the end of a child's small
intestine protrudes into the large intestine.
- Evaluate abdominal
symptoms such as altered bowel habits,
anemia, or unexplained weight loss.
How To Prepare
Before a barium enema, tell your health professional if you:
- Are or might be pregnant.
- Are
allergic to latex. Latex products are commonly used to administer the contrast
material. If you have a latex allergy, different products will be
used.
- Know that you are allergic to barium.
- Have had an
upper digestive barium test (upper GI or barium swallow) recently.
The preparation for a barium enema usually involves a very thorough
cleansing of the large intestine, because the colon must be completely clear of
stool and gas. Even a small amount of stool can affect the accuracy of the
test.
- For 1 to 3 days before the test, you will
usually be on a
clear liquid diet.
- On the day before the
test:
- You should drink very large amounts of
noncarbonated clear liquids, unless your health professional has advised you
not to.
- You will then take a combination of laxatives (such as
castor oil, magnesium citrate, or bisacodyl) to empty your
intestines.
- You may be asked to take a tap water
enema to clean any remaining stool from your
colon.
- On the day of the test, you may need to repeat
the enema until the liquid that passes is free of any stool particles.
Sometimes a
rectal suppository or a commercially prepared enema,
such as a Fleet enema, is used instead of a tap water enema.
Talk to your health professional about any concerns you have
regarding the need for this test, its risks, how it will be done, or what the
results will indicate. To help you understand the importance of this test, fill
out the
medical test
information form
(What is a PDF document?).
How It Is Done
To make the intestine visible on an X-ray picture, the colon is
filled with a contrast material containing barium. This is done by pouring the
contrast material through a tube inserted into the
anus. The barium blocks X-rays, causing the
barium-filled colon to show up clearly on the X-ray picture.
- You will lie on the X-ray table while a
preliminary X-ray film is taken.
- While you are
lying on
your side
, a well-lubricated enema tube will be inserted gently into
your rectum. The barium contrast material is then allowed to flow slowly into
your colon.
- A small balloon on the enema tip may be inflated to
help you hold in the barium. Tightening your anal sphincter muscle (as if you
were trying to hold back a bowel movement) against the tube and taking slow,
deep breaths may also help.
- Occasionally, you may be given an
injection of medication to relieve the cramping.
Your health professional will observe the flow of the barium
through your colon on an X-ray
fluoroscope monitor that is similar to a television
screen.
- You will be asked to turn to different
positions, and the table may be tilted slightly to help the barium flow through
your colon and to take X-rays from different directions (sides, front, and
back).
- Your health professional may also press gently on your
abdomen with his or her hand or a plastic paddle to help move the barium
through your intestines.
- If a double-contrast study is being done,
the barium will be drained out and your colon will be filled with air.
When the test is finished:
- The enema tube is then removed.
- You will be given a bedpan or be taken to the toilet to get rid of
as much of the barium as you can.
- One or two additional X-ray
pictures (post-evacuation films) will then be taken.
A single-contrast study usually takes 30 to 45 minutes, although
the actual time the barium is held inside is only 10 to 15 minutes. A double-
or air-contrast study may take up to an hour.
After the test, you may resume your regular diet unless otherwise
instructed. Be sure to drink plenty of liquids to replace those you have lost
and to help flush the remaining barium out of your system. Your bowel movements
may look white or pinkish for 1 to 2 days after the test.
How It Feels
A barium enema procedure can be uncomfortable and tiring, but
usually it does not last very long.
Many people report that the preparation and bowel cleaning are the
most difficult parts of the test. The castor oil has an unpleasant taste, and
the frequent bowel movements can be tiring. Also, the anal area can become
quite sore during the process. Warm
sitz baths or a local anesthetic salve, such as
Preparation H, can help ease this discomfort.
You may be embarrassed by the test. You may worry that you won't be
able to hold the barium and that it will leak onto you or onto the table. The
health professionals who perform this procedure are accustomed to this and will
be able to help you.
The X-ray table is hard and sometimes cold because air-conditioning
is used to keep the equipment cool. When the barium first flows into your
colon, it may feel a bit cool. As your colon fills, you may feel a sensation of
fullness, moderate cramping, and a strong urge to have a bowel movement. If an
air-contrast study is performed, you may feel increased cramping or gas pains
from having gas pumped into your large intestine. Taking slow, deep breaths
through your mouth can help you relax.
You may feel tired for a day or so after the test. You should
arrange for someone to drive you home after the test. This test can be
exhausting.
Risks
There is very little risk of complications from having a barium
enema.
- Occasionally the barium remaining in the colon
hardens, causing severe constipation (impaction) or obstruction. To decrease
the risk of impaction, drink extra fluids following the procedure and, if
necessary, take an enema or mild
laxative after the test.
- In rare cases,
barium can cause inflamed areas in the colon called barium
granulomas.
- Perforation of the bowel is a more serious, but very
rare complication. Under the pressure from the barium or air, a weakened
section of the colon may break open, allowing the intestinal contents to spill
into the abdominal cavity. It may occur in people whose bowel wall has been
weakened by intestinal problems, such as inflammatory bowel diseases,
ulcerative colitis, or Crohn's disease.
Call your health professional immediately if you:
- Have rectal bleeding
- Have severe
abdominal pain.
- Develop a fever.
- Do not have a bowel
movement within 2 days after the test.
Results
A barium enema, or lower gastrointestinal (GI) examination, is an
X-ray examination of the large intestine (colon and rectum).
The results of a barium enema are usually available immediately
after the test or within a few days.
Barium enema
Normal: |
The colon appears normal. See an illustration of a
barium
enema X-ray .
|
Abnormal: |
One or more problems in the colon are detected, such
as:
- A section of colon did not fill with
barium.
- An obstruction or narrowing (stricture) in the
bowel.
- Polyps or growths on the inner wall of the
colon.
- Sacs in the colon wall (diverticulosis).
- Structural defects and
inflammation (colitis) of the lining of the colon.
- A narrowed
segment or a twisted loop of bowel, causing an
obstruction.
- Telescoped bowel can be seen in a child, indicating
intussusception. The barium enema may be used as a treatment to return the
bowel to its normal position.
|
Many conditions can change barium enema test results. Your health
professional will discuss any significant abnormal results with you in relation
to your symptoms and medical history.
What Affects the Test
Factors that can interfere with your test or the accuracy of the
results include:
- Stool or gas in the colon.
- Muscle
spasms in the colon wall.
- Inability to remain still or to cooperate
during the test.
- Extreme
obesity.
What To Think About
- A barium enema is less expensive and has fewer
risks than
colonoscopy and
sigmoidoscopy. It does not require sedation. However,
small colon polyps are more likely to be missed during a barium enema. For more
information, see the medical tests
Colonoscopy and
Sigmoidoscopy.
- Polyps cannot be removed
during a barium enema. Further evaluation with a colonoscopy is generally
recommended if abnormal results are found during a barium enema.
- If
your health professional suspects you have an abdominal mass, other tests may
be needed before or after a barium enema. These include abdominal X-rays,
ultrasound studies, and
computed tomography (CT) scans.
- A flexible
sigmoidoscopy provides a more direct view of the rectum and sigmoid colon,
where more than half of colon polyps are usually found. For more information,
see the medical test
Sigmoidoscopy.
- If an
upper gastrointestinal series is planned, it should be
performed after the barium enema. The barium swallowed during an upper GI
series may take several days to pass through the intestine and thus can
interfere with the results of a barium enema.
- A barium enema should
not be done if you have a rapid, irregular heartbeat (tachycardia), severe
ulcerative colitis,
toxic
megacolon, acute
diverticulitis, or if a perforation of the intestine
is suspected. If a contrast enema is necessary but there is an increased risk
of an intestinal perforation, a water-soluble contrast (Gastrografin) may be
used instead of barium. Gastrografin decreases the risk for problems that could
result if the bowel is perforated.
- Because a developing baby (fetus) is very
sensitive to radiation, such as from X-rays, this test is not done during
pregnancy.
References
Other Works Consulted
-
Chernecky CC, Berger BJ, eds. (2004). Laboratory Tests and Diagnostic Procedures, 4th ed.
Philadelphia: Saunders.
-
Fischbach FT, Dunning MB III, eds. (2004).
Manual of Laboratory and Diagnostic Tests, 7th ed.
Philadelphia: Lippincott Williams and Wilkins.
-
Handbook of Diagnostic Tests
(2003). 3rd ed. Philadelphia: Lippincott Williams and Wilkins.
-
Pagana KD, Pagana TJ (2002). Mosbys
Manual of Diagnostic and Laboratory Tests, 2nd ed. St. Louis:
Mosby.
Credits
Author
|
Sydney Youngerman-Cole, RN, BSN, RNC |
Editor
|
Susan Van Houten, RN, BSN, MBA |
Associate Editor
|
Tracy Landauer |
Primary Medical Reviewer
|
Patrice Burgess, MD - Family Medicine |
Specialist Medical Reviewer
|
Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology |
Last Updated
|
June 28, 2005 |
Barium Enema |
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Last updated: June 28, 2005
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This information is not intended to replace the advice of a doctor.