title: An endoscopic study on the duodenal ulcer. An endoscopic classification of the duodenal ulcer and its clinical implications.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004381:Duodenal Ulcer / Q000145:classification* / Q000473:pathology; D004384:Duodenoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence