Mayo score for ulcerative colitis32
| Mayo index | 0 | 1 | 2 | 3 |
| Stool frequency | Normal | 1–2/day more than normal | 3–4/day more than normal | 5/day more than normal |
| Rectal bleeding | None | Streaks of blood with stool <50% of the time | Obvious blood with stool most of time | Blood passed without stool |
| Mucosa (endoscopic subscore) | Normal or inactive disease | Mild disease (erythema, decreased vascular pattern, mild friability) | Moderate disease (marked erythema, lack of vascular pattern, friability, erosions) | Severe disease (spontaneous bleeding, ulceration) |
| Physician’s global assessment | Normal | Mild disease | Moderate disease | Severe disease |
Mayo score=sum of scores for each of the four variables (maximum score 12).
Clinical response: reduction of baseline Mayo score by ≥3 points and a decrease of 30% from the baseline score with a decrease of at least one point on the rectal bleeding subscale or an absolute rectal bleeding score of 0 or 1.
Clinical remission: defined as a Mayo score ≤2 and no individual subscore >1.
Mucosal healing: defined as a mucosa subscore of ≤1.
Disease activity: Mild 3–5; Moderate 6–10; Severe 11–12.