A barium swallow, also called an esophagogram, is an imaging test that checks for problems in the upper GI tract. The upper GI tract includes your mouth, back of the throat, esophagus, stomach, and first part of your small intestine. The test uses a special type of x-ray called fluoroscopy. Fluoroscopy shows internal organs moving in real time. The test also involves drinking a chalky-tasting liquid that contains barium. Barium is a substance that makes parts of your body show up more clearly on an x-ray.