Table 3.

Changes from original (Lyon 1.0) to updated (Lyon 2.0) criteria for the modern diagnosis of GERD

	Original Lyon 1.0 criteria	Updated Lyon 2.0 criteria	Retired criteria
Overall		Concepts of different testing strategies in unproven versus proven GERD
Endoscopy	No criteria for endoscopy performed on therapy	Separate criteria added for testing performed on therapy
Conclusive endoscopic evidence off therapy	LA C, D oesophagitis	LA B, C, D oesophagitis
Borderline endoscopic evidence off therapy	LA A, B oesophagitis	LA A ooesophagitis
Adjunctive endoscopic evidence off therapy	Histopathology (score) Electron microscopy (DIS) Low mucosal impedance	Hiatus hernia Histopathology scoring systems Electron microscopy of biopsies	Routine oesophageal biopsy analysis Endoscopy-based mucosal impedance assessment
pH or pH impedance	No separation between testing off and on antisecretory therapy	Separate thresholds for testing off and on antisecretory therapy
wireless pH monitoring	No criteria for wireless pH monitoring	Wireless monitoring thresholds added
pH impedance monitoring	No thresholds for baseline impedance	Thresholds added for mean nocturnal baseline impedance	Postreflux swallow induced peristaltic wave index
High-resolution manometry	Analysis of motor diagnoses using Chicago Classification version 3.0	Analysis of motor diagnoses using Chicago Classification version 4.0

DIS, dilated intercellular spaces; GERD, gastro-oesophageal reflux disease; LA, Los Angeles.