title: Upper gastrointestinal hemorrhage: early diagnostic approaches.
mesh_terms: D000792:Angiography; D001466:Barium Sulfate; D003951:Diagnostic Errors; D004064:Digestive System / Q000000981:diagnostic imaging; D004384:Duodenoscopy; D004945:Esophagoscopy; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis*; D005773:Gastroscopy; D006801:Humans
chemical_list: D001466:Barium Sulfate