title: Delimitation of clinical materials in gastroenterology.
mesh_terms: D003093:Colitis, Ulcerative / Q000175:diagnosis; D003951:Diagnostic Errors; D004381:Duodenal Ulcer / Q000175:diagnosis; D005767:Gastrointestinal Diseases / Q000145:classification* / Q000601:surgery; D006801:Humans; D011379:Prognosis