The ingestion of barium sulfate to outline the esophagus, stomach, and small intestines during x-ray or fluoroscopic examination. The exam may be used as an alternative to endoscopy to diagnose reflux, dysphagia, peptic disease, or other upper gastrointestinal conditions. Also called upper G.I. series.

PROCEDURE
If the exam or procedure does not follow a barium enema, the patient should receive nothing by mouth after midnight on the night before the test. No food or liquids should be taken by mouth until the last image is produced. If the test is done within a few days after a barium enema examination, it is important to be sure the colon is free of barium, which could interfere with visualization of the stomach and intestines. A cleansing enema the evening before the test may remove residual barium from the colon.