title: Letter: Upper gastrointestinal endoscopy.
mesh_terms: D004386:Duodenum; D004564:Electrocoagulation / Q000009:adverse effects*; D004724:Endoscopy / Q000009:adverse effects*; D004945:Esophagoscopy / Q000009:adverse effects; D005773:Gastroscopy / Q000009:adverse effects; D006801:Humans; D008309:Mallory-Weiss Syndrome / Q000601:surgery*