Lower gastrointestinal series
A barium enema is given in order to perform an X-ray examination of the large intestines. Pictures are taken after rectal instillation of barium sulfate (a radiopaque contrast medium).
How the test is performed
This test may be done in an office or a hospital radiology department. You lie on the X-ray table and a preliminary X-ray is taken. You are asked to lie on your side while a well-lubricated enema tube is inserted gently into your rectum.
Barium, a radiopaque (shows up on X-ray) contrast medium, is then allowed to flow into your 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 (expand) it and provide better images.
You are asked to move into different positions and the table is slightly tipped to get different views. At certain times when the X-ray pictures are taken, you hold your breath and be still for a few seconds so the images won’t be blurry.
The enema tube is removed after the pictures are taken and you are given a bedpan or helped to the toilet. You then expel as much of the barium as possible. One or two X-rays may be taken after the barium is expelled.
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 taken. This gives a more detailed picture. The enema tube is then removed, and you again empty the colon.
How to prepare for the test
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.
For Infants and children:
The preparation you can provide for this test depends on your child’s age and experience. For specific information regarding how you can prepare your child, see the following topics:
- infant test or procedure preparation (birth to 1 year)
- toddler test or procedure preparation (1 to 3 years)
- preschooler test or procedure preparation (3 to 6 years)
- schoolage test or procedure preparation (6 to 12 years)
- adolescent test or procedure preparation (12 to 18 years)
How the test will feel
There is a feeling of fullness during the procedure, moderate to severe cramping, the urge to defecate, and a general discomfort. The X-rays themselves are painless.
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.
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
- Crohn’s disease (regional enteritis)
- 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 perforated colon, which is very rare.
CT scans and ultrasounds are now the tests of choice for the initial evaluation of abdominal masses.
by Martin A. Harms, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.