Pediatrics Disorders of Gastrointestinal System Including Diarrhea 18df632e The Gold standard investigation for Gastro-Oesophageal reflux disease is: A Endoscopy B 24 hour esophageal pH recording C Oesophageal manometry D Measurement of length of lower oesophageal sphincter High-Yield Explanation 24 hour Esophageal pH recording provides a quantitative & sensitive documentation of acidic reflux episodes.