The Gold standard investigation for Gastro-esophageal reflux disease is:
Endoscopy
24 hour pH recording
Oesophageal manometry
Measurement of length of lower oesophageal sphincter
b. 24 hour pH recording(Ref: Nelson's 20/e p1787-1788, Ghai 8/e p 280)Extended esophageal pH monitoring of distal esophagus, provides a quantitative sensitive documentation of acidic reflux episodes, the most important type of reflux episodes for pathologic reflux
Gastro Intestinal System