This summary was prepared by Dr Felicity Goodyear-Smith, Goodfellow Unit, Department
of General Practice & Primary Health Care, University of Auckland and Dr Stephen
Wood, Radiology Registrar, Auckland.
Barium Enema
About Barium Enema
Endoscopic examination of the upper bowel: oesophagoscopy and gastroscopy -
Procedure Details
Barium studies (X-rays) of the bowel are used to diagnose abnormalities of the gastrointestinal
tract, such as tumours, ulcers and other inflammatory conditions, polyps, hernias,
and obstructions (strictures).
Description of Procedure
A barium enema involves filling the large intestine with barium liquid while X-ray
images are taken.
Barium studies involve X-rays of the GI tract taken in conjunction with the use
of a diluted barium sulphate solution lining the area of the bowel under examination..
Barium sulphate is a radiopaque metallic contrast medium. Often the studies are
termed double contrast by virtue of use of gas as a second contrast medium.
A barium enema involves filling the large intestine with barium liquid while X-ray
images are taken. This may involve either single or double contrast images. For
single contrast procedures, the colon is filled with barium liquid and X-ray images
reveal any significant prominent abnormalities in the large intestine. With double
contrast, which is usually the barium study of choice, a smaller quantity of thicker
barium liquid is introduced to the large intestine, followed by air. This allows
the barium to form a film on the inner surface, allowing smaller surface abnormalities
of the large intestine to be detected and assessment of the state of the bowel mucosa.
A barium enema is usually performed on an outpatient basis. To prevent obscuring
of the image, it necessary for the large bowel to be emptied of faeces prior to
the examination. This is vital as faecal residue can mimic the appearance of a polyp.
Bowel preparation involves the patient drinking clear fluids during the preceding
day; using a laxative and having nil by mouth for some hours prior to the procedure.
The patient ideally needs to be passing clear stools prior to the commencement of
the study.
The patient is positioned on an X-ray table and the barium liquid introduced per
rectum via an enema tube. During double contrast imaging, the colon is also inflated
with air through the same rectal tube with a small hand pump.
Advantages of Barium Enema:
- In comparison to colonoscopy, barium enema is safer. The perforation rate for Barium
enema is 1:25000, compared with 1:1700 for endoscopy.
- Available
resource. It is difficult to compare costs between barium studies and
endoscopy and they may be of comparable costs. However is some centres barium studies
are much more accessible to GPs and may be arranged with much less delay for the
patient than colonoscopy.
Disadvantages of Barium Enema:
- Not able to take samples or provide treatment as part of the procedure.
- Radiation exposure. Dose is 5-10 millisieverts compared with chest film 0.06 millisieverts
and background radiation of 2 millisieverts per year. Users of ionising radiation
are required to inform all women of child bearing age about the risks of radiation
in pregnancy. Pregnancy is a relative contraindication to the use of radiation but
generally in the context of the barium enema the urgency is such that can delay
or choose alternative investigation.
- Not as comprehensive or accurate method for diagnosis of some conditions in comparison
to colonoscopy. For example, one study found that barium enema X-ray may missed
60% of adenomatous polyps detected using a colonoscope.
- Dangerous in the presence of toxic megacolon but this condition would in all likelihood
be suspected by clinical presentation, plain X-ray or preliminary film, or during
filling with barium and prior to pumping in air.
Potential difficulties that may arise out of a barium enema referral:
- Bowel preparation is reasonably arduous and can make frail, elderly people feel
quite unwell.
- People are prone to constipation are occasionally not cleared adequately on the
usual preparation and need an extra day.
- Rolling around/lying on the table is hard and uncomfortable (patients need to
be able to roll through 360 degrees and lie prone and supine. A good indication
is that a person who can climb onto an examination couch without too much assistance
can generally tolerate a double contrast study.
- Discomfort of air insufflation.
- Where buscopam injection is used to relax bowel for better pictures, patients may
experience some blurring of vision.
- Tendency of barium to cause constipation in the days following the procedure.
- Need for an interpreter in non-English speaking patients.
Indications for Barium Enema:
- Abdominal pain
- Bleeding from the rectum or melena
- Change in bowel habit
- Chronic diarrhoea or constipation
- Unexplained weight loss or anaemia
- Palpable mass (with suspicion that it arises from bowel)
- Unusual bloating
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Images from a Barium Enema
Click on these images for an enlarged view - opens in a separate window which you
will need to close.
Normal Barium Enema |
Ulcerative Colitis Descending Colon |
Crohn's Disease Transverse Colon |
Pendunculated Polyp Descending Colon |
Colon Carcinoma Mid Transverse Colon |
Colon Carcinoma Descending Colon |
Diverticular Disease Sigmoid Colon |
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Patient Information
This patient information is
available as a PDF file from which you may print copies - you will need
an acrobat reader.
Information for the Patient on Barium Enema
Most facilities will provide a local information sheet and this information should
be considered in conjunction with that.
In order to diagnose a possible problem in your colon, an X-ray examination called
a barium enema has been requested. The colon (also called large intestine or large
bowel) is the last portion of your digestive tract. It starts at the caecum, which
attaches to the end of the small intestine, and ends at the rectum. The colon is
a hollow tube, about one and a half metres long, and its main function is to store
unabsorbed food products prior to their elimination.
A plain X-ray gives minimal detail about the inside of the bowel. Standard X-rays
show very good details of bony structures but less detail of soft tissues and hollow
organs such as the intestine. However when its lining is coated with a liquid containing
barium, irregularities of the surface of the bowel can be seen on X-ray. A barium
enema can therefore be useful in diagnosing conditions such as polyps, tumours and
diverticula (small pockets in the wall of the colon).
In a barium enema, the barium liquid is inserted into the bowel via a tube in the
anus. Usually it is followed by the pumping in of some air. The air and the barium
provide a double contrast for X-rays and allow for smaller abnormalities of the
bowel surface to be detected by X-ray. An injection may be given during the procedure
which helps the bowel to relax.
Preparation:
- The large intestine requires a thorough cleansing to allow a clear view of the bowel
lining. This means the bowel must be completely free of all solid waste.
- To achieve this you will be given a special diet and laxatives to use the day before
your test. The actual regime varies from centre to centre. You will be given instructions
on what you need to do by staff from the radiology unit, which you must follow carefully.
- You will be given a list of foods you are permitted to eat (and those that are forbidden)
for 3 days before the investigation. The bowel preparation is a safe regimen and
generally involves drinking several litres of a fluid which induces diarrhoea and
thoroughly cleanses the lining of the bowel. Some centres use laxative tablets or
enemas to help in the cleansing process.
- Once you have taken the preparation fluid you will be required to fast (have nil
by mouth) or have clear fluids only until after the procedure.
The Procedure:
- The examination is conducted by a radiologist (a doctor specialising in medical
diagnosis by X-ray) and a radiographer (a technician trained in the use of medical
X-ray equipment).
- You will be positioned on an examination table, and a tube will be inserted through
your anus to allow the barium to flow into the intestine.
- During the procedure, the X-ray machine and your examination table will move and
you may be asked to change positions. This involves lying on your front, back and
both sides, and being able to roll over completely.
- When the barium fills your colon it may feel like you need to move your bowel. However
the shape of the end of the enema tube helps keep the barium in. You may also experience
some mild cramping for a short period of time during the procedure. This is due
to the distension of the bowel by barium or air.
- After the procedure, a small amount of barium will be expelled by the body immediately.
The remainder of the liquid is excreted in later bowel motions.
Risks and Potential Complications:
- Barium enema is a very safe procedure and complications are extremely rare. Despite
the bowel preparation and some discomfort during the procedure most people tolerate
it very well.
- After the examination your bowel will expel the barium, which is not absorbed by
your body. Barium liquid may cause constipation. Following the examination you should
eat foods high in fibre and drink plenty of fluids to help expel the barium from
the body. Your faeces (stool) will have a whitish colour to it until the barium
has all been passed. You may be required to take a mild laxative.
- X-ray procedures should be avoided wherever possible during pregnancy. If you are
pregnant (or suspect you might be), please make sure that the doctors, nurses and/or
technicians caring for you know this before you have a barium enema.
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