Table 3

 Montreal classification of severity of ulcerative colitis (UC)

SeverityDefinition
ESR, erythrocyte sedimentation rate.
S0Clinical remissionAsymptomatic
S1Mild UCPassage of four or fewer stools/day (with or without blood), absence of any systemic illness, and normal inflammatory markers (ESR)
S2Moderate UCPassage of more than four stools per day but with minimal signs of systemic toxicity
S3Severe UCPassage of at least six bloody stools daily, pulse rate of at least 90 beats per minute, temperature of at least 37.5°C, haemoglobin of less than 10.5 g/100 ml, and ESR of at least 30 mm/h