The "captive bolus" test and the pinchcock at the diaphragm. An esophageal pump and some non-diseases of the esophagus.
D004935:Esophageal Diseases / Q000175:diagnosis*; D005753:Gastric Mucosa / Q000175:diagnosis*; D005764:Gastroesophageal Reflux / Q000175:diagnosis; D005769:Gastrointestinal Motility / Q000502:physiology; D006356:Heartburn / Q000209:etiology; D006548:Hernia, Diaphragmatic / Q000175:diagnosis; D006801:Humans; D014636:Valsalva Maneuver