Barium enema

About barium enema

A barium enema is a test that uses X-rays to examine your large bowel (colon and rectum).

Your bowel contains air and so it lets most X-rays pass through easily. This means it doesn't show up well on plain X-ray images. However, if your bowel wall is coated with barium, a white liquid that X-rays don't pass through, the lining of your bowel shows up clearly on X-ray images.

The test is often done as an outpatient procedure in a hospital's imaging or radiology department. It’s usually carried out by a radiographer (a health professional trained to perform imaging procedures). A radiologist (a doctor who specialises in using imaging methods to diagnose medical conditions) may also be present.

A barium enema test is particularly useful for helping your doctor to diagnose conditions that can affect the lining of your bowel, such as polyps, diverticular disease and cancers of the colon or rectum.

What are the alternatives to barium enema?

There are several alternative procedures to a barium enema. These are listed below.

  • Computerised tomography colonography (CTC). This uses X-rays to make a three-dimensional image of your bowel and is also called ‘virtual colonoscopy’.
  • MRI (magnetic resonance imaging). This uses magnets and radiowaves to produce images of your bowel.
  • A colonoscopy. This allows a doctor to look inside your bowel using a narrow, flexible, tube-like telescopic camera called a colonoscope.

You may need to have a combination of tests before your condition is diagnosed. Your doctor will explain the options available to you.

Preparing for a barium enema

Your radiographer will explain how to prepare for your examination.

To get good X-ray images, it's essential for your bowel to be completely empty so that the barium, which acts like a temporary paint, can coat every part of your bowel lining. To achieve this, you will be asked not to eat any solid food and drink only clear liquids the day before your test.

You will usually be given two doses of a strong laxative to rinse out your bowel. You will receive instructions on how and when to take it. You will probably pass lots of watery faeces. Stay close to a toilet for several hours after taking the treatment and drink clear fluids to prevent getting dehydrated.

It's important to follow the bowel preparation instructions carefully. If your bowel isn't completely empty, the images from the test will be incomplete and you may need to have the test again.

If you usually take medicines, continue to take them as prescribed unless your doctor specifically tells you not to. It's important to tell your radiographer about any medicines you're taking and if you have any allergies, glaucoma or heart disease.

If you're a woman of childbearing age, you will be asked if you're pregnant. A barium enema isn't recommended for pregnant women, unless there is an urgent medical reason. It’s important to tell your radiographer if you could be pregnant.

Your radiographer will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

If you take tablets or insulin for diabetes, you will be given some specific advice about what to do before the test.

What happens during a barium enema

The test usually takes 15 to 20 minutes, but you will probably be in the radiology department for up to an hour.

In a private cubicle, you will be asked to remove your clothing and put on a hospital gown. You will be taken to the X-ray room and asked to lie down on the X-ray table.

You may be given an injection of a muscle relaxant to help relax the muscles of your bowel wall either at the start or during the procedure. If you have glaucoma, you should tell your radiographer so he or she can give you a different injection.

Your radiographer will gently pass a soft plastic tube into your rectum. During the examination, the barium will flow through the tube to coat your bowel wall. Your radiographer will also gently pump air or carbon dioxide gas through the tube to expand your bowel and make the bowel wall easier to see. You may find this slightly painful but it won't last for long.

You may feel as if you want to open your bowels. However, it's important to try to hold the barium fluid and air in.

Images of your bowel will be displayed on a monitor and you will be moved into different positions, both to help the barium flow and to see as much of the bowel as possible. The X-ray table will slowly tilt to get you into position.

Your radiographer will take several X-ray images, or a moving series of images, with you in different positions. When your radiographer or radiologist has recorded enough images, he or she will remove the tube.

The procedure may cause some discomfort. You may have cramp-like pains that continue for a short while after the procedure.

What to expect afterwards

You will probably want to go to the toilet and pass out the barium when the procedure is over.

You will usually be able to go home when you feel ready. If you were given muscle relaxants, wait an hour before driving.

Take it easy at home and stay within reach of a toilet for the first few hours. Try to drink clear fluids – enough so that you aren't thirsty – and eat vegetables, fruit and high-fibre foods. This will help to maintain regular bowel movements and prevent constipation.

A report will be sent to the doctor who requested your test. This can take two weeks to reach your doctor.

What are the risks?

As with every procedure, there are some risks associated with a barium enema. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your radiographer or radiologist to explain how these risks apply to you.

You will be exposed to some X-ray radiation during the procedure. In all X-ray examinations, the amount of radiation is kept to the absolute minimum that is necessary. The level of exposure from having a barium enema is about the same as you would receive naturally from the environment over about three years.

If you’re pregnant

Pregnant women are generally advised not to have X-ray tests of their abdomen as there is a risk the radiation may cause some damage to their unborn child, particularly in early pregnancy. Tell your doctor or radiographer if there is a chance you could be pregnant.


Side-effects are the unwanted but mostly temporary effects you may get after having the procedure.

After having a barium enema you may feel bloated for a short while. You may also feel constipated for a few days and may need to take a mild laxative.

The muscle relaxant that is commonly used for this test can temporarily blur your eyesight, give you a dry mouth and make it harder than usual to pass urine – and/or make you need to go more urgently.


Complications are when problems occur during or after the procedure.

It's very rare, but you may have a reaction to the bowel cleansing preparation. This could include dehydration and the loss of too many salts from your body, which can cause you to collapse or have a fit.

During the test, there is a very small chance that your bowel may be damaged or perforated. For this reason, you won't be offered a barium enema if you may already have an inflamed or weakened bowel wall.

Is it safe to have barium inside my bowel?


Yes, it's generally safe to have barium inside your bowel but it may produce a few side-effects.


Barium is a white liquid that shows up on X-ray images. It's safe for you to have barium inside your stomach or bowels, but it may cause you to have mild constipation and you may notice that it turns your faeces white. This should only last for a day or so and your faeces will return to usual once the barium has passed through. Contact your GP if these side-effects continue for more than two days. He or she may give you a laxative to help your bowel get rid of the barium more quickly.

Who interprets my barium enema results?


The pictures produced during your barium enema will be examined by a radiologist, a doctor who specialises in using imaging methods to diagnose medical conditions.


A radiologist will write a report based on the images recorded during your barium enema. Most hospitals in the UK now use digital equipment to record the images, which means they are stored on computer rather than film. If you have been sent for a barium enema by your GP, he or she will receive the report.

The amount of time it takes for your results to come through to your referring doctor will depend on why you're having the test. If your results are urgent, your GP will ensure that he or she makes a note on the scan request form and your results will arrive sooner. You can ask your GP when he or she expects your results to be ready.

Aren't barium enemas old-fashioned?


A barium enema can still be a useful test, particularly in screening for bowel cancer. It has a proven safety record and is inexpensive for local hospitals to provide. However, other tests, particularly colonoscopy and CT scans, are now often used instead and have been shown to be less unpleasant.


For many years a barium enema was the best test for looking at the lining of your large bowel. Local hospitals usually have the staff and equipment to offer the test, with radiographers who are skilled in performing the test and radiologists (doctors who specialise in using imaging methods to diagnose medical conditions).

A CT scan or a colonoscopy may not be so readily available, or may be unsuitable for you. Ask your GP for information on the pros and cons of the different types of test.