The gold standard for diagnosis of gastroesophageal reflux disease (GERD) is:
Barium swallow- IOC for diagnosis of Hiatus hernia and Zenker's diveicula Endoscopy + Biopsy- IOC for diagnosis of Barret's esophagus 24 hours PH monitoring- Gold standard Investigation for GERD Esophageal manometry- IOC for diagnosis of motility disorders of esophagus like Achalasia cardia, Diffuse esophageal spasm and Nut cracker's esophagus.
Barium swallow
Endoscopy
24-hours pH monitoring
Esophageal manometry
Esophagus