This test is used to view your swallowing function. You will be asked to swallow a variety of barium-coated substances, such as liquid, applesauce, and a cracker. Barium is a whitish paste that allows the substances to light up under an X-ray so the examiner can determine how these substances are moving through your mouth, pharynx, and esophagus. It is different from a Barium Swallow in that it analyzes the swallowing function, specifically, which the Barium Swallow does not do. You can eat or drink before this exam.