Total Mayo score = stool-frequency subscore + rectal-bleeding subscore + endoscopic subscore + physician global assessment. Each subscore is 0–3, for a total of 0–12.

Domain	0 points	1 point	2 points	3 points
Stool frequency over the past 3 days	Normal	1–2 stools above normal	3–4 stools above normal	≥5 stools above normal
Rectal bleeding over the past 3 days	None	Streaks 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: erythema, reduced vascular pattern and mild friability	Moderate: marked erythema, absent vascular pattern, friability and erosions	Severe: spontaneous bleeding and ulceration
Physician global assessment	Normal	Mild disease	Moderate disease	Severe disease

Total score	Implemented activity band
0–2	Remission or minimal activity range
3–5	Mild activity
6–10	Moderate activity
11–12	Severe activity

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