title: Letter: Upper gastrointestinal endoscopy.
mesh_terms: D001466:Barium Sulfate; D004415:Dyspepsia / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005069:Evaluation Studies as Topic; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005773:Gastroscopy; D006801:Humans; D011859:Radiography; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging
chemical_list: D001466:Barium Sulfate