X-rays to examine the esophagus, stomach, and small intestine. X-ray pictures are taken after one has swallowed a barium suspension (contrast medium). See also barium enema . X-rays are a form of electromagnetic radiation (like light). They are of higher energy, however, and can penetrate the body to form an image on film. Structures that are dense (such as bone) will appear white, air will be black, and other structures will be shades of gray. Barium is very dense and will appear white on the X-ray film.

Alternative Names

GI series; Barium swallow X-ray; Upper GI series