In barium enema, the contrast dye barium sulfate is introduced into the lower gastrointestinal (GI) tract, and x-rays are used to visualize the large intestine, or colon. The barium, which is opaque to x-rays, sharply outlines the inner lining of the colon, revealing any structural or tissue abnormalities. In the single-contrast test, barium sulfate alone is used, while in the double-contrast test, both barium sulfate and air are instilled to provide more detailed views.
Purpose of the Barium Enema
- To detect polyps and malignant (cancerous) tumors of the colon and rectum
- To assess the type, extent, and severity of inflammatory bowel disease
- To detect diverticula (abnormal outpouchings) and other structural changes in the colon
- To diagnose symptoms such as chronic diarrhea, blood in stools, constipation, irritable bowel syndrome (IBS), unexplained weight loss, changes in bowel habits, suspected blood loss and abdominal pain
Who Performs Barium Enema
Special Concerns about Barium Enema
- Pregnant women should not undergo this test because exposure to ionizing radiation may harm the fetus.
- This test is not appropriate for people with an extremely dilated colon (megacolon) or those with certain types of abnormal heart rhythms.
- When perforation of the colon is suspected, a water-soluble contrast agent is used instead of barium, and the normal pretest intestinal cleansing is not performed.
- Barium in the abdomen from previous contrast x-rays, such as a barium swallow, may interfere with the results. If x-rays of the entire digestive tract are required, the barium enema is usually scheduled first.
Before Barium Enema
- Tell your doctor if you are taking any medications or have allergies, especially to barium or iodinated contrast materials. Also inform your doctor if you have recently been ill or have another medical condition.
- Inform your doctor if you are pregnant or could possibly be pregnant.
- Cleansing your intestine before the test is essential to produce adequate anatomic detail on the x-rays. Your doctor will give you specific instructions.
- Typically, on the day before the procedure you are asked to consume only clear liquids (such as water, bouillon, or gelatin dessert); to drink a glass of water or another clear fluid every hour for 8 to 10 hours; and to take an oral laxative agent at specified times. You should not eat or drink anything after midnight on the day of the test.
- On the morning of the procedure, you may be instructed to self-administer a cleansing enema before leaving your home, or you may be given an enema at the testing facility.
- Remove jewelry, dentures, eye glasses and any metal objects or clothing that may interfere with x-rays. Wear a hospital gown.
What You Experience
- You are instructed to lie on your side on a table with your knees drawn to your chest.
- The doctor gently inserts the lubricated enema tube into your rectum, and barium is allowed to flow into your colon. A small balloon at the tip of the enema tube may be inflated to help keep the barium inside.
- The radiologist observes the flow of barium through the colon with the aid of fluoroscopy, which transmits continuous, moving x-ray images onto a viewing screen.
- At various points during the examination, you will be instructed to move into different positions as spot x-ray films are taken of any abnormalities. As each x-ray is taken, you should hold your breath and remain as still as possible.
- If you are having a double-contrast x-ray, the doctor instills small amounts of air through the enema tube and additional x-ray films are taken. The air helps the barium adhere to the colon wall, making it possible to visualize small polyps and tumors.
- You may experience mild abdominal cramps or the urge to defecate while the barium or air is being introduced into the intestine. Breathe deeply and slowly through your mouth to help ease this discomfort.
- After all the required x-ray images are taken, you will be escorted to the toilet or provided with a bedpan.
- The procedure lasts about 30 to 45 minutes.
Risks and Complications of Barium Enema
- The test involves exposure to low levels of radiation.
- The barium may accumulate and block the intestine if it is not expelled within a day or two; a mild oral cathartic or cleansing enema can resolve the problem.
- A rare complication is perforation of the colon. This risk is higher for the double-contrast than the single-contrast test, and when the colon is weakened by inflammation, tumor, or infection.
After Barium Enema
- Drink extra fluids to prevent dehydration and help eliminate the barium. Your doctor may also give you a mild laxative to help purge the barium from your body.
- Your stool will be chalky and light-colored initially, but should return to normal color in 1 to 3 days.
- Be sure to rest after the procedure; many patients find the test itself and the bowel preparation that precedes it to be exhausting.
Barium Enema Results
- The doctor will examine the x-ray images for any abnormality, including polyps, tumor, or signs of inflammatory bowel disease.
- If a definitive diagnosis can be made based on the images, appropriate treatment will be initiated.
- Additional tests, such as colonoscopy, may be needed to obtain a tissue sample (biopsy) for definitive diagnosis of colorectal cancer or inflammatory bowel disease.
The Johns Hopkins Consumer Guide to Medical Tests
Simeon Margolis, M.D., Ph.D., Medical Editor
Updated by Remedy Health Media