Barium Enema

(BE, Lower Gastrointestinal Series, Lower GI Series, Colon X-ray)

Procedure Overview

What is a barium enema?

A barium enema is a radiographic (x-ray) examination of the lower gastrointestinal (GI) tract. The large intestine, including the rectum, is made visible on x-ray film by filling the colon with a liquid suspension called barium.

X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body tissues onto specially-treated plates (similar to camera film) and a “negative” type picture is made (the more solid a structure is, the whiter it appears on the film).

Fluoroscopy is often used during a barium enema. Fluoroscopy is a study of moving body structures - similar to an x-ray “movie.” A continuous x-ray beam is passed through the body part being examined, and is transmitted to a TV-like monitor so that the body part and its motion can be seen in detail. In a barium enema, fluoroscopy allows the radiologist to see the movement of the barium through the large intestine as it is instilled through the rectum.

Why is barium used with x-rays?

Barium is a dry, white, chalky, metallic powder that is mixed with water to make barium liquid. Barium is an x-ray absorber and appears white on x-ray film. When instilled via the rectum, barium coats the inside wall of the large intestine so that the inside wall lining, size, shape, contour, and the colon’s patency are visible on x-ray. This process shows differences that might not be seen on standard x-rays. Barium is used only for diagnostic studies for the GI tract.

The use of barium with standard x-rays contributes to the visibility of various characteristics of the large intestine. Some abnormalities of the large intestine that may be detected by a barium enema include tumors, inflammation, polyps (growths), diverticula (pouches), obstructions, and changes in the intestinal structure.

After the instillation of barium into the rectum, the radiologist may also fill the large intestine with air. Air will appear black on x-ray film, contrasting with barium’s white image. The use of the two substances, barium and air, is called a double contrast study.

The purpose of using two contrast substances is to achieve an enhancement of the inside wall lining of the large intestine. As the air expands the large intestine (like blowing up a balloon), a barium coating is formed on the inner surface of the colon wall. This technique enhances visualization by sharpening the outline of the inner surface layer of the large intestine. The benefit of this technique is to show smaller surface abnormalities in the large intestine.

Other related procedures that may be used to diagnose lower GI problems include colonoscopy, abdominal x-ray, computed tomography (CT scan) of the abdomen, and abdominal ultrasound. Please see these procedures for additional information.

Anatomy of the colon:

Illustration of the anatomy of the digestive system, adult

The large intestine, or colon, has four sections:

  • ascending colon - extends upward on the right side of the abdomen
  • transverse colon - extends from the ascending colon across the body to the left side
  • descending colon - extends from the transverse colon downward on the left side
  • sigmoid colon - named because of its S-shape; extends from the descending colon to the rectum

The rectum joins the anus, or the opening where waste matter passes out of the body.

Reasons for the Procedure

A barium enema may be performed to diagnose structural or functional abnormalities of the large intestine, including the rectum. These abnormalities may include, but are not limited to, the following:

  • ulcerative colitis - ulcerations and inflammation of the large intestine
  • Crohn’s disease - ulcerations and inflammation occurring in any part of the GI tract (mouth to anus)
  • infection or inflammation, such as diverticulitis (inflammation of pouches of the colon wall)
  • obstructions and polyps (growths)
  • cancer
  • unusual bloating or lower abdominal pain
  • changes in bowel movements, such as chronic diarrhea or constipation, or passing of blood, mucus, and/or pus

There may be other reasons for your physician to recommend a barium enema.

Risks of the Procedure

You may want to ask your physician about the amount of radiation used during the procedure and the risks related to your particular situation. It is a good idea to keep a record of your past history of radiation exposure, such as previous scans and other types of x-rays, so that you can inform your physician. Risks associated with radiation exposure may be related to the cumulative number of x-ray examinations and/or treatments over a long period of time.

If you are pregnant or suspect that you may be pregnant, you should notify your physician. Radiation exposure during pregnancy may lead to birth defects.

Patients who are allergic to or sensitive to medications, contrast dyes, iodine, shellfish, or latex should notify their physician.

Constipation or fecal impaction may occur if the barium is not completely eliminated from the body.

Risks of barium enema may include, but are not limited to, the following:

  • colon perforation
  • water intoxication (excess intake of water) from cleansing enemas prior to the procedure
  • constipation or fecal impaction

Contraindications for a barium enema include, but are not limited to, the following:

  • suspected bowel perforation
  • severe ulcerative colitis
  • pregnancy
  • toxic megacolon
  • acute abdominal pain

There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your physician prior to the procedure.

Certain factors or conditions may interfere with the accuracy of a barium enema procedure. These factors include, but are not limited to, the following:

  • recent barium swallow or upper GI procedure that may interfere with the x-ray exposure of the lower GI area
  • colon spasm
  • stool in the bowel

Before the Procedure

  • Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
  • You may be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear.
  • You will be asked to fast for eight hours before the procedure, generally after midnight. You may be given additional instructions about a special diet for one to two days prior to the procedure.
  • If you are pregnant or suspect that you may be pregnant, you should notify your physician.
  • Notify your physician if you are sensitive to or are allergic to any medications, latex, tape, and anesthetic agents (local and general).
  • Notify your physician of all medications (prescribed and over-the-counter) and herbal supplements that you are taking. Your physician may advise you to withhold certain medications prior to the procedure.
  • Your physician will instruct you about specific ways to prepare your bowel for the test. You may be asked to take a laxative, undergo an enema, use a rectal laxative suppository, and/or drink a special fluid that helps prepare your bowel.
  • Notify the radiologist if you have had a recent barium swallow or upper GI procedure, as this may interfere with obtaining an optimal x-ray exposure of the lower GI area.
  • Based upon your medical condition, your physician may request other specific preparation

During the Procedure

A barium enema may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your physician’s practices.

Generally, a barium enema will follow this process:

  1. You will be asked to remove any clothing, jewelry, or other objects that may interfere with the procedure.
  2. If you are asked to remove clothing, you will be given a gown to wear.
  3. You will be positioned horizontally on the examination table in a side-lying position.
  4. A rectal tube will be inserted into the rectum to allow the barium to flow into the intestine.
  5. The barium will be allowed to flow slowly into the intestine. You may experience cramping in the lower abdominal area as the barium is instilled. To lessen the discomfort, it may be helpful to take slow deep breaths.
  6. You may feel the need to have a bowel movement. It will be important to resist the urge to prevent the barium from leaking back out. At the appropriate time, you will be given a bedpan or assisted to the bathroom as needed.
  7. During the procedure, the machine and examination table will move and you may be asked to assume various positions as the x-rays are being taken.
  8. The radiologist will take single pictures, a series of x-rays, or a video (fluoroscopy) as the barium moves through the intestine.
  9. If a double contrast study is ordered, you will be asked to evacuate some of the barium. A bedpan or access to a bathroom will be provided. Some barium will remain in your intestine. Air is injected via the rectum in order to expand the large intestine, and more x-rays will be taken.
  10. Once all required x-rays have been taken, you will be assisted from the table.

After the Procedure

Following the examination, some barium will be expelled immediately. You will be assisted to the bathroom or given a bedpan.

You may resume your normal diet and activities after a barium enema, unless your physician advises you differently.

Barium may cause constipation or possible impaction after the procedure if it is not completely eliminated from your body. You may be advised to drink plenty of fluids and eat foods high in fiber to expel the barium from the body. You may also be given a cathartic or laxative to help expel the barium.

Since barium is not absorbed into the body but passes through your entire gastrointestinal tract, your bowel movements may be lighter in color until all of the barium has been excreted.

The long and rigorous bowel preparation prior to the procedure may cause fatigue afterwards. You should rest as needed.

You may experience soreness of the anus and rectum due to the bowel preparation. Your physician may recommend the application of a soothing ointment to the area.

Notify your physician to report any of the following:

  • difficulty with bowel movements or inability to have a bowel movement
  • pain and/or distention of the abdomen
  • stools that are smaller in diameter than normal

Your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.

Online Resources

The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. Please consult your physician with any questions or concerns you may have regarding your condition.

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American Cancer Society

American Gastroenterological Association

National Cancer Institute (NCI)

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

National Institutes of Health (NIH)

National Library of Medicine