Montreal classification

Choose the disease, then the features. The Crohn's disease code is age, location and behaviour, with p added for perianal disease and L4 added for upper gastrointestinal disease.

DiseaseCrohn's diseaseUlcerative colitis

Crohn's: age at diagnosisA1: 16 or youngerA2: 17 to 40A3: over 40

Crohn's: locationL1: terminal ileumL2: colonL3: ileocolonL4: upper gastrointestinal tract only

Crohn's: upper gastrointestinal disease as well (adds L4 to L1 to L3)

Crohn's: behaviourB1: non-stricturing, non-penetratingB2: stricturingB3: penetrating

Crohn's: perianal disease (p)

Ulcerative colitis: maximum extentE1: proctitis, limited to the rectumE2: left-sided, distal to the splenic flexureE3: extensive, proximal to the splenic flexure

Ulcerative colitis: current severityS0: clinical remissionS1: mild; 4 or fewer stools a day, with or without blood, no systemic illness, normal inflammatory markersS2: moderate; more than 4 stools a day with minimal signs of systemic toxicityS3: severe; 6 or more bloody stools a day, pulse 90 or more, temperature 37.5 °C or more, haemoglobin below 105 g/L, ESR 30 mm/h or more

Enter the values above.

References

Silverberg MS, Satsangi J, Ahmad T, et al. Toward an integrated clinical, molecular and serological classification of inflammatory bowel disease: report of a Working Party of the 2005 Montreal World Congress of Gastroenterology. Can J Gastroenterol. 2005;19 Suppl A:5A-36A.

Satsangi J, Silverberg MS, Vermeire S, Colombel JF. The Montreal classification of inflammatory bowel disease: controversies, consensus, and implications. Gut. 2006;55(6):749-753.