A barium enema, or lower gastrointestinal (GI) examination, is an X-ray examination of the large intestine (colon and rectum). The test is used to help diagnose diseases and other problems that affect the large intestine. To make the intestine visible on an X-ray picture, the colon is filled with a contrast material containing barium. This is done by pouring the contrast material through a tube inserted into the anus. The barium blocks X-rays, causing the barium-filled colon to show up clearly on the X-ray picture.
There are two types of barium enemas.
- In a single-contrast study , the colon is filled with barium, which outlines the intestine and reveals large abnormalities.
- In a double-contrast or air-contrast study , the colon is first filled with barium and then the barium is drained out, leaving only a thin layer of barium on the wall of the colon. The colon is then filled with air. This provides a detailed view of the inner surface of the colon, making it easier to see narrowed areas (strictures), diverticula, or inflammation.
In some cases, the single-contrast study may be preferred for specific medical reasons or for older people who may not be able to tolerate the time-consuming and somewhat more uncomfortable double-contrast study. But if the results are not clear, a double-contrast study may also be done.
Why It Is Done
A barium enema is done to:
- Identify inflammation of the intestinal wall that occurs in inflammatory bowel diseases, such as ulcerative colitis or Crohn's disease. A barium enema also may be used to monitor the progress of these diseases.
- Find problems with the structure of the large intestine, such as narrowed areas (strictures) or pockets or sacs (diverticula) in the intestinal wall.
- Help correct a condition called ileocolic intussusception , in which the end of a child's small intestine protrudes into the large intestine.
- Evaluate abdominal symptoms such as pain, blood in stool, or altered bowel habits.
- Evaluate other problems such as anemia or unexplained weight loss.
How To Prepare
Before a barium enema, tell your doctor if you:
- Are or might be pregnant.
- Are allergic to latex. Latex products are commonly used to administer the contrast material. If you have a latex allergy, different products will be used.
- Know that you are allergic to barium.
- Have had an upper digestive barium test (upper GI or barium swallow) recently.
- Have had a colonoscopy or sigmoidoscopy recently.