Lower GI Series (barium enema)

A lower gastrointestinal series is an x-ray examination of the large intestine. It is also known as a barium enema, since this is part of the procedure. Barium is a white, chalky substance that makes the colon, or large intestine, visible on an x-ray.

This test is done to evaluate:

• altered bowel habits

• lower abdominal pain

• blood, mucus, or pus in the stool

• suspicion of cancer or inflammatory disease and

• obstructions or structural changes in the colon

The colon must be clear for this test. The person avoids dairy products and stays on a liquid diet for 24 hours prior to the test. He or she should drink at least 5 glasses of water during this period. The patient performs a cleansing enema at home the morning of the test.

During the test, the person assumes various positions on an x-ray table. The examiner puts barium slowly into the rectum through a lubricated tube. The person may have some cramps or an urge to defecate. It is important for the person to keep the anal muscle contracted around the tube. This prevents leakage of barium. The examiners follow the flow of barium with a fluoroscope, which uses continuous x-rays to show movement. Various still x-rays are also taken. At the end of the test, the tube is removed and the patient is asked to expel as much barium as possible. He or she then returns to the table for a final x-ray of the empty colon. Sometimes a second test follows, where the examiner pumps air into the colon for additional x-rays.

A barium enema is a relatively safe test. There is a slight risk of puncturing the colon. Rarely, patients may have an inflammatory response to the barium. Doctors do not perform this test on people with severe active colitis or a suspected puncture in the colon.

Copyright (c) 1998. HBO & Company (602) 230-7575. All Rights Reserved.