Incidence and Paris Classification of Pediatric Inflammatory Bowel Disease

Table 3

Comparison of Montreal and Paris Classifications for ulcerative colitis based on Levine et al. [13].

	Montreal Classification	Paris Classification
Extent	E1: ulcerative proctitis; E2: left-sided UC (distal to splenic flexure); E3: extensive (proximal to splenic flexure)	E1: ulcerative proctitis; E2: left-sided UC (distal to splenic flexure); E3: extensive (hepatic flexure distally); E4: pancolitis (proximal to hepatic flexure)
Severity	S0: clinical remission; S1: mild UC; S2: moderate UC; S3: severe UC	S0: never severe*; S1: ever severe*

∗Severe defined by Pediatric Ulcerative Colitis Activity Index (PUCAI).