Alternative Names : Lower gastrointestinal series
Barium enema is a special x-ray of the large intestine, which includes the colon and rectum. Before x-rays are taken, a liquid called barium sulfate is placed in the rectum. The liquid is a type of contrast. Contrast highlights specific areas in the body, creating a clearer image. The barium eventually passes out of the body with the stools.
Because the colon and rectum are normally not visible on x-rays, you need to temporarily coat their inner surfaces with barium, a liquid that does show up on x-rays. This makes the outline of these organs visible on the x-ray pictures. This test is useful for diagnosing cancers and diverticuli (small pouches that may form in the intestinal wall).
How do you prepare for the test?
Tell your doctor if there is any chance you might be pregnant. If you have diabetes and take insulin, discuss this with your doctor before the test.
You will be given very specific instructions to ensure that your colon is completely empty before the test. You may be told to eat only a light breakfast and a liquid lunch and dinner (such as broth, fruit juice, or plain gelatin) on the day before the test. You may also be instructed to drink a large amount of clear liquid between meals and to avoid dairy products. You will need to take a laxative, a medicine that stimulates your intestine to move things through more quickly, so that you have a bowel movement to empty the colon. It is a good idea to stay at home or at least near a bathroom for a few hours after taking the laxative. On the day of the test, do not eat any breakfast.
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 will then be told to lie on your side. The health care provider will gently insert a well-lubricated tube (enema) into your rectum. The tube is connected to a bag that contains the barium. The barium flows into your colon.
A small balloon at the tip of the enema tube may be inflated to help keep the barium inside your colon. The health care provider monitors the flow of the barium on an x-ray fluoroscope screen, which is like a TV monitor.
You must completely empty your bowels before the exam. This may be done using an enema or laxatives combined with a clear liquid diet. Your health care provider will give you specific instructions. Thorough cleaning of the large intestine is necessary for accurate pictures.
There are two types of barium enemas:
1.Single contrast barium enema uses barium to highlight your large intestine.
2.Double contrast barium enema uses barium, but also delivers air into the colon to expand it. This allows for even 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 are still for a few seconds so the images won’t be blurry.
The enema tube is removed after the pictures are taken. You will be given a bedpan or helped to the toilet, so you can empty your bowels and remove as much of the barium as possible. One or two x-rays may be taken after you use the bathroom.
What happens when the test is performed?
You wear a hospital gown and lie on a table in the radiology department. To administer the enema, a nurse pushes a small tube an inch or two into your rectum, and then uses this tube to fill your colon and rectum with barium liquid. You may find the sensation of the filling of your colon somewhat strange (you might feel like you need to have a bowel movement), but it is not painful.
The x-ray for this test is taken as a video that begins immediately after your enema is started. The x-ray video is taken by a large camera positioned over your abdomen. Usually the room is darkened while the video is taken so that the doctor can watch the pictures on a TV screen. If the doctor wants to save a view in “freeze frame” (developed later for a closer look), you may be asked to hold your breath for a few seconds so that your breathing movement does not blur the image. A few more pictures may be taken after the lights are turned back on. After this, you are asked to empty your bowel in a nearby bathroom.
Usually one picture is taken of your abdomen after you have had your bowel movement, to make sure that the bowel has emptied well.
How the Test Will Feel
When barium enters your colon, you may feel like you need to have a bowel movement. You may also have a feeling of fullness, moderate to severe cramping, and general discomfort. Try to take long, deep breaths during the procedure. This may help you relax.
There are no significant risks. You will be exposed to a small amount of radiation during the test. The amount of radiation from a barium enema is larger than from a simple chest x-ray, but still very small — too small to be likely to cause any harm.
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.
Must you do anything special after the test is over?
In some cases, if some stool was still present in your colon despite your preparation the day before, the test must be repeated.
How long is it before the result of the test is known?
It takes the x-ray department 30 minutes to an hour to develop the pictures from your barium enema, and it will take additional time for a doctor to examine the x-rays and to decide how they look. Typically you can get the results within a day or two.
Normal Results: Barium should fill the colon evenly, showing normal bowel shape and position and no blockages.
What Abnormal Results Mean
Abnormal test results may be a sign of:
*Twisted loop of the bowel