A barium enema is an x-ray examination of the colon and rectum. The colon and rectum make up the large intestine, which plays an important role in the body's ability to process waste. A barium enema outlines the colon and rectum and shows abnormalities, such as inflammation, polyps, and colon cancer.

About the procedure

Barium is a contrast medium (a substance that helps show the colon better on the x-ray) that is introduced into the colon through a lubricated enema tip. When an x-ray is taken, the barium shows up bright white, clearly defining the outline of the colon.

The medical team

A barium enema is performed in an x-ray room in either a hospital or a doctor's office. The test is performed by a radiology technician who is specifically trained in performing this kind of test, and a radiologist — a medical doctor who performs and interprets imaging tests. The radiologist interprets the results of the barium enema and confirms or diagnoses any abnormalities of the colon.

Questions to ask your doctor

Before your barium enema, consider asking your doctor the following questions:

• Why are you recommending this test?
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• Who will perform the barium enema, and who else will be in the room?
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• What will happen during the barium enema?
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• How long will the procedure take?
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• Will it be painful?
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• Are there risks associated with having a barium enema?
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• What if I don't have this examination?
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• Will I need to avoid any activities after the barium enema?
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• When will I learn the results?
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• Who will explain the results to me?
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• What further tests will be necessary if the results indicate cancer?

Preparing for the procedure

When you schedule the examination, you will get detailed instructions on how to prepare for your barium enema.

Review with your doctor or nurse what you need to do to prepare for your barium enema, and whether you should take your regular medications that day. In addition, tell your doctor about all medications you are taking, as well as any drug allergies, especially allergy to contrast medium. You will also need to tell the doctor about any medical conditions you may have. Women should tell their doctors if there is any chance that they are pregnant.

Because your colon must be empty, you will need to be on a restricted diet consisting of either soft foods or clear liquids for one to three days prior to the procedure. This means only eating foods such as fat-free bouillon or broth, black coffee, strained fruit juice, and gelatin.

In addition to the restricted diet, you will need to take a laxative or give yourself an enema the day or night before the barium enema. If your doctor prescribes a laxative, it will either be given as a pill or as a powder that you will mix with water before drinking. In either form, the laxative will make you use the bathroom frequently, so it may be a good idea to stay close to home during this time. You will not be able to eat or drink anything after midnight the day of your examination. It is important that your colon is completely empty to ensure a thorough examination.

During the procedure

A barium enema usually takes 20 to 30 minutes to complete. Before the procedure begins, you will be given a hospital gown to wear. You will need to remove all clothing including underwear, jewelry, and any other metal objects that can interfere with the x-ray image. If you are a woman of child bearing age, the radiologist will ask if there is any possibility that you are pregnant, since the test involves x-rays that expose your pelvic area to radiation, which is harmful to a fetus.

You will lie on your side on an examination table in a private room, and a sheet will be draped over your body. The examination table is attached to a fluoroscope (a special x-ray unit attached to a video monitor). The fluoroscope views the internal structure of the colon. The x-ray technologist will begin the exam by performing several x-rays to make sure that your colon is empty. A well-lubricated enema tip attached to a tube will be inserted into your anus. The radiologist will then insert barium into your colon through this tube. You may be asked to move into several different positions during the test so that the barium can flow through the entire colon. Once the radiologist has determined that there is a sufficient amount of barium in the colon, a small amount of air may be delivered into the colon through the same tube to distend (inflate) the bowel so a better view of the intestinal wall can be obtained; this is called a double contrast barium enema. Several x-rays will be taken during this time.

You may feel some mild abdominal pressure and cramping when the barium is flowing through the colon. Taking slow, deep breaths may alleviate this discomfort. You may also feel discomfort from lying still for an extended period of time. Once the barium has been inserted into the colon, you may also feel the urge to have a bowel movement. It is important that you try and hold in the barium until the examination is complete.

After the procedure

Once the radiologist has determined that enough images of the colon have been taken, the enema tip will be removed and you will be helped down from the table and can go to the restroom to expel the barium. You will then return to the examination room where an additional x-ray picture will be taken to make sure you have emptied your bowel sufficiently.

You may notice a gray or white stool for several days following a barium enema as the remaining barium is expelled. Since barium can cause constipation (infrequent or difficult passage of stool), you may also be asked to take a laxative to help remove whatever barium is left. Be sure to drink plenty of fluids for the next several days to help prevent constipation. If you feel severe abdominal pain or have a fever, bloody bowel movements, dizziness or weakness, call your doctor immediately.

You can expect to resume your normal activities following the barium enema, but it may be a good idea to have someone accompany you to the test so they can drive you home.

Additional resources

American College of Gastroenterology: Commonly Performed Radiographic Tests in Gastroenterology: Barium Enema

MedlinePlus Interactive Tutorials: Barium Enema

MedlinePlus Medical Encyclopedia: Barium Enema

More Information

Diagnosing Cancer: Tests and Procedures

Cancer.Net Guide to Colorectal Cancer

Colonoscopy—What to Expect