Total Mayo score = sum of four subscores (0–3 each; total 0–12): stool frequency, rectal bleeding, mucosal appearance at endoscopy, and physician's global assessment.

Domain	0	1	2	3
Stool frequency (vs baseline, past 3 days)	Normal	1-2 stools more than normal	3-4 stools more than normal	≥5 stools more than normal
Rectal bleeding (past 3 days)	None	Streaks of blood with stool <50% of the time	Obvious blood with stool most of the time	Passing blood alone
Mucosal appearance at endoscopy	Normal or inactive disease	Mild disease: erythema, decreased vascular pattern, mild friability	Moderate disease: marked erythema, absent vascular pattern, friability, erosions	Severe disease: spontaneous bleeding, ulcerations
Physician global assessment	Normal	Mild disease	Moderate disease	Severe disease

Total Mayo score = sum of the four domain scores (0–12).

Mayo Score/Disease Activity Index (DAI) for Ulcerative Colitis