title: Endoscopy in the diagnosis of upper gastrointestinal bleeding.
mesh_terms: D000368:Aged; D005260:Female; D005336:Fiber Optic Technology; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis*; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged