title: What is a normal upper gastrointestinal tract?
authors.forename: A P
authors.initials: AP
authors.lastname: Walker
authors.forename: B F
authors.initials: BF
authors.lastname: Walker
authors.forename: I
authors.initials: I
authors.lastname: Segal
mesh_terms: D000368:Aged; D004032:Diet; D005767:Gastrointestinal Diseases / Q000517:prevention & control*; D006801:Humans; D013019:South Africa