Endoscopic classification of the squamocolumnar junction (SCJ)
| Group | Location of SCJ | Appearance of SCJ |
| I | Within 2 cm above gastro-oesophageal junction | Unremarkable, (i.e. relatively straight on insufflation of air) |
| II (eccentric SCJ) | As above | Eccentric, irregularly serrated on insufflation of air |
| II (tongues of Barrett’s oesophagus) | As above | “Tongue(s)” and/or islands of columnar epithelium extending into the distal oesophagus |
| II (segments of Barrett’s oesophagus) | Shifted >2 cm above gastro-oesophageal junction (i.e. circumferential segment of columnar mucosa) | Any, mostly irregular with additional tongues |