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
narrowed areas (strictures),
diverticula, 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. But if the results are not clear, a double-contrast study may also be
done.
Why It Is Done
A barium enema is done to:
- 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.
- Find 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 pain, blood in stool, or altered bowel habits.
- Evaluate other problems such as anemia or unexplained weight loss.
How To Prepare
Before a barium enema, tell your
doctor 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.
- Have had a colonoscopy or sigmoidoscopy 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 doctor has advised you not
to.
- You will then take a combination of laxatives 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 doctor about any concerns you have regarding
the need for this test, its risks, how it will be done, or what the results
will mean. 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 medicine to relieve the cramping.
Your doctor 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 doctor 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. Your doctor may recommend you take a medicine, such as a
laxative, to help you pass the rest of the barium.
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 hardest parts of the test. The laxative may have 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 doctors 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.
The test may take awhile, so you may want to bring something to do quietly (like a book or magazine to read).
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
your doctor recommends it, 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 doctor immediately if you:
- Have rectal bleeding.
- Have severe
abdominal pain.
- Develop a fever.
- Do not have a bowel
movement within several 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 a picture 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
doctor will discuss any significant abnormal results with you in relation to
your symptoms and past health.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Stool or gas in the colon.
- Muscle
spasms in the colon wall.
- A rapid, irregular
heartbeat (tachycardia).
- Severe ulcerative colitis, toxic megacolon, acute
diverticulitis, or a suspected perforation of the intestine.
- Pregnancy.
- Inability to remain still or to cooperate
during the test.
- Extreme
obesity.
- A barium swallow test (upper gastrointestinal series) done within a week before the test.
What To Think About
- If your doctor thinks 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.
- 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 may be used to screen for colon cancer. Other tests are used more often to screen for colon cancer. This test
is less expensive and has fewer risks than
colonoscopy and
sigmoidoscopy. And it does not require sedation. But
small colon polyps are more likely to be missed during a barium enema. For more
information, see the topics Stool Tests for Colorectal Cancer,
Colonoscopy, Sigmoidoscopy, and Virtual Colonoscopy.
References
Other Works Consulted
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Saunders.
- Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Credits
| By | Healthwise Staff |
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| Primary Medical Reviewer | Kathleen Romito, MD - Family Medicine |
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| Specialist Medical Reviewer | Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology |
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| Last Revised | April 25, 2011 |
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