Clinical remission (Full Mayo): Score ≤ 2 with no individual subscore > 1.
Clinical response: Decrease ≥ 3 points from baseline AND ≥ 30% reduction from baseline AND decrease ≥ 1 point in rectal bleeding.
Mucosal healing: Mayo Endoscopic Subscore ≤ 1 (allow for minimal mucosal changes).
STRIDE-II 2021 treat-to-target: Aim for both symptomatic remission AND endoscopic remission (MES ≤ 1).
Section 4
Next Steps
Clinical Actions
01
Remission (≤ 2): Maintain current therapy; reassess in 3–6 months; colonoscopy for surveillance per guidelines.
02
Mild–Moderate (3–10): Optimise 5-ASA; consider topical therapy; biologics if 5-ASA-refractory.
03
Severe (≥ 11): Consider IV steroids if not already; surgical IBD team referral; apply Oxford Acute Severe Colitis Criteria (Travis).
04
All patients: Check stool cultures, C. diff, faecal calprotectin; review drug adherence.
Section 5
Evidence Appraisal
Primary Reference
Coated oral 5-aminosalicylic acid therapy for mildly to moderately active ulcerative colitis
Schroeder KW et al. • New England Journal of Medicine. 1987;317(26): 1625–1629
Section 6
Literature
Development
The Mayo Score was developed as the primary efficacy endpoint by Klaus-Werner Schroeder, William Tremaine, and Duane Ilstrup at the Mayo Clinic, published in the New England Journal of Medicine in 1987 as part of a double-blind trial of coated oral 5-aminosalicylic acid (olsalazine). The four-domain structure was designed to capture clinically relevant dimensions of UC severity in a format suitable for serial trial assessment.
Regulatory & Trial Legacy
The Mayo Score became the de facto regulatory endpoint for UC clinical trials following its use in aminosalicylate and early biologic licensing studies. The FDA and EMA have required Mayo Score-based primary endpoints (full Mayo or partial Mayo without endoscopy) for most UC drug approvals. The Partial Mayo Score (without endoscopic subscore) was later validated by Lewis et al. (2008) as an outpatient monitoring tool.
