title: In vivo measurements of the gastrointestinal tract. Hiatus hernia and achalasia.
mesh_terms: D000126:Achlorhydria / Q000175:diagnosis*; D004931:Esophageal Achalasia / Q000175:diagnosis*; D004941:Esophagitis / Q000175:diagnosis*; D005745:Gastric Acidity Determination; D006548:Hernia, Diaphragmatic / Q000175:diagnosis*; D006801:Humans