Inflammatory bowel disease in pediatric and adolescent patients: A biomolecular and histopathological review

Table 2 Montreal and Paris classifications for ulcerative colitis

	Montreal classification		Paris classification
Extent	E1	Ulcerative proctitis	E1	Ulcerative proctitis
	E2	Leftsided colitis distal to splenic flexure	E2	Leftsided colitis distal to splenic flexure
	E3	Extensive colitis distal to hepatic flexure	E3	Extensive colitis proximal to splenic flexure
Severity	S0	Clinical remission	E4	Pancolitis, proximal to hepatic flexure
	S1	Mild ulcerative colitis	S0	Never severe
	S2	Moderate ulcerative colitis	S1	Ever severe
	S3	Severe ulcerative colitis