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.