title: A new method for occult blood research of gastric origin: evaluation during endoscopic investigation.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005766:Gastrointestinal Contents / Q000032:analysis; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis*; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D009780:Occult Blood