Barium enema

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science

This page was updated on September 12, 2022.

One of the best ways for a doctor to diagnose colorectal cancer and other abnormalities in the lower gastrointestinal tract is with X-rays during a barium enema procedure.

What is a barium enema?

A barium enema is an examination of the lower gastrointestinal (GI) tract. During a barium enema test, images are taken of the large intestine and rectum. To see better, radiologists use a contrast material called barium, which is a white chalky liquid that coats the intestinal tract. Barium absorbs X-rays, making it easier for the radiologist to examine what’s going on inside.

The liquid barium is inserted into the rectum before the exam through an enema. Air is also inserted to help make the images sharp.

Why is a barium enema performed?

In addition to detecting colorectal cancer, a barium enema is used to look for:

Barium enema prep

To prepare for a barium enema, the patient may be asked to do the following:

  • Don’t eat a day or two before the procedure, as directed. It’s OK to have clear liquids (such as juice, tea, black coffee, broth or soda), but the patient may be asked to avoid most other liquids, including dairy products.
  • Don’t consume anything by mouth after midnight on the day of the procedure.

It’s important that the colon be empty, so the patient may need to take a pill or liquid laxative (as directed by a doctor) to prepare the evening or a few hours before the procedure.

The patient should also make prior arrangements to have someone drive home after the procedure.

Be sure to tell the care team if the patient:

  • Is pregnant or breastfeeding.
  • Is allergic to contrast materials, iodine or seafood.
  • Has had recent illnesses or any type of surgery involving the colon or rectum.
  • Has any concerns about insurance or co-pays before the scheduled appointment.

Barium enema procedure

The barium enema procedure takes about 30 to 60 minutes and has four steps:

  • Preparation and rectal exam
  1. When the patient arrives at the facility, he or she may be asked to change into a hospital gown. The patient will also need to remove any jewelry, dental appliances, eyeglasses or other metal objects that could interfere with the X-ray equipment.
  2. The patient may be asked to lie on his or her side on the X-ray table while a quick image is taken to make sure the bowel is empty.
  3. The radiologist or technologist performs a digital rectal exam (DRE) to feel for any bumps or abnormalities.
  • Enema placement
  1. For the enema, a lubricated tip attached to a tube is inserted into the rectum.
  2. A technologist delivers a liquid barium solution through the tube to coat the colon.
  3. The colon may also be filled with a small amount of air or carbon dioxide (CO2) to help it expand for better visibility.
  • X-ray images
  1. The table is raised or tilted in different ways while X-rays are taken as the barium works its way through the colon.
  2. The technologist may ask the patient to hold his or her breath or move in different positions to get better images and move the barium through the entire colon.
  3. The exam shouldn’t be painful. The patient may experience cramps or feel as though a bowel movement is imminent. Slow, deep breaths may help the patient feel more comfortable.
  • Emptying the bowels
  1. Once the test is complete, the enema tube is removed.
  2. The patient may go to the bathroom and expel what’s left.
  3. After the patient has gone to the bathroom, he or she may be asked to return to the exam room so more X-rays can be taken to confirm the bowels have cleared enough of the barium solution.

What to expect after a barium enema

The patient may notice gray or white stools for several days after the barium X-ray. Post-test, it may be a good idea to:

  • Drink lots of fluid to help remove the remaining barium and prevent constipation.
  • Ask the care team about taking a laxative, if necessary.

If the patient experiences any of the following, call the doctor’s office right away:

  • Fever Severe stomach pain
  • Blood in stool
  • Dizziness
  • Weakness

Barium X-ray results

The care team may order additional views or imaging tests, depending on the results. The patient may be asked to repeat the test in a few months to determine whether a colorectal cancer treatment is working or the tumor has changed.

Barium enema side effects

While problems with lower gastrointestinal (GI) barium enemas are unlikely, possible risks include:

  • Belly cramps
  • Constipation
  • Possible blockage in the gut

Also rare, barium may leak through a hole in the lower GI tract that wasn’t seen and inflame surrounding tissues.

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