What Is a Barium Enema?

X-rays show doctors what's happening inside your body. They produce helpful images of your bones, fat, muscle, and even the air in your lungs. But when it comes to your colon, X-rays aren't as clear.

To get the best detail possible, doctors use what’s called a barium enema. Also called a colon X-ray, a barium enema is a two-part procedure.

Barium is a white, chalky powder. A technician mixes it with water and passes it through a small tube in your rectum.

This barium mixture covers the lining of your colon and lets your doctor take images of it at work, highlighting anything that may be causing trouble.

Why Would I Have One?

If you're having any of these issues, a barium enema can help your doctor narrow down the cause:

What Conditions Does It Look For?

A barium enema covers conditions from your rectum to your small intestine. These include:

Are There Any Risks With the Test?

Because X-rays of any kind may harm a baby in the womb, they're usually not given to pregnant women.

Though the amount of radiation you get is low, too much radiation from X-rays can potentially cause cancer. But the chance of getting cancer is small when compared to the benefit of how easily a barium enema can diagnose a problem.

In rare cases, barium enemas can cause the following complications:

How Do I Prepare?

To get the best images of your colon, it needs to be completely empty. Anything left in your colon might be considered part of the problem.

Your doctor will have specific instructions -- follow them carefully. Make sure it's OK to take your regular medications and supplements.


Here's what you can expect:

A special diet. The day before the exam, you may be asked to steer clear of all solid food and drink clear liquids only, such as broth and tea.

Nothing after midnight. This is called fasting. Prepare to stop eating and drinking at midnight before the exam.

Take a laxative. The night before your exam, you may be asked to take a laxative in pill or liquid form to empty your colon.

Colon cleaning. Your doctor may suggest you use an enema kit, which has a solution that cleans all residue from your colon.

As is the case with other X-rays, you may be asked to take off any jewelry, metal objects, eyeglasses, and dental devices that could alter the images.

What Happens During the Test?

Since you're not able to eat or drink before the procedure, most barium enemas are given in the morning. It usually takes 30 minutes to an hour.

Two people will guide you through the barium enema: the radiology technician and a radiologist, a physician who's trained to perform and read the X-rays. Here's how it works:

You'll lie on your side on a table and have an X-ray to make sure your colon is completely clean.

An enema tube will be eased into your rectum. A bag with the barium liquid will be attached. Near the tip of the tube, there will be a balloon. This keeps the barium inside your body.

As the barium flows into your colon, you may feel cramping or the urge to have a bowel movement. This may feel uncomfortable. Try to breathe and relax so the tube stays in place. You don’t want the barium to leak out. If needed, you can be given a bedpan or taken to a bathroom.

Air may also be pumped in to help the barium cover every part of your colon.

The radiologist may ask you to hold your breath and turn different ways so images can be taken from various angles. The radiologist may also press on your stomach area to move your colon into a better position for X-rays.

Once the radiologist is finished, some of the barium will flow back through the tube into the bag. You can release the rest of the barium, and the air, in the restroom.

The test usually takes around 40 minutes, but the exact time will vary for each person.


What Happens After the Test?

To make sure all the barium is out of your body, you may be given a laxative or an enema. You should be able to eat and drink normally afterward. You may have white bowel movements as the barium works its way out of your system.

Call your doctor if you feel constipated, don't have a bowel movement for 2 days after the exam, or are having a hard time passing gas rectally.

What Do the Results Mean?

The radiologist will examine the images and send a report to your doctor. There are two kinds of results:

A positive result means the radiologist found abnormalities in your colon.

A negative result means your colon is working normally.

If you have a positive result, expect to have more tests that will either look deeper into the issue, monitor it for change, biopsy an area, or remove a growth.

WebMD Medical Reference Reviewed by Carmelita Swiner, MD on January 23, 2020



Mayo Clinic: "X-ray," “Barium enema.”

Radiology info: “X-ray (Radiography) -- Lower GI Tract.”

Johns Hopkins Health Library: “Barium Enema.”

Cancer Research UK: “Barium X-Ray.”

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