Modified Barium Swallow Study
A modified barium swallow study is x-ray imaging of a person swallowing items of different consistencies. The materials are laced with barium sulfate, allowing them and the anatomy of the esophagus to be visualized. Barium swallow studies are used to detect dysphagia, hiatal hernias, gastroesophageal reflux disease, tumors and other problems of the esophagus.
(Image found on Imgur)