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AGA IPMN Risk Stratification (2015)AIMS65 Score APACHE II (AP-specific application)ASGE Choledocholithiasis Risk Stratification ATLAS Score (CDI Treatment Response)Adenoma Detection Rate (ADR) Benchmark Amsterdam II Criteria (Lynch)Anorectal Manometry Interpretation (ARM)Aronchick Bowel Preparation Scale BISAP Score Barrett's Dysplasia Grading (Vienna Classification)Boston Bowel Preparation Scale (BBPS)Bristol Stool Form Scale CD Perianal Disease Activity Index (PDAI)CDI Severity Classification (IDSA/SHEA 2021)CT Severity Index (CTSI — Balthazar)Caecal Intubation Rate (CIR) Benchmark Cambridge Classification (CP — ERCP/EUS/CT)Celiac Disease Serology Interpreter Chicago Classification v4.0 (HRM)Colorectal Cancer TNM Staging (AJCC 8th Edition)Colorectal Submucosal Invasion (Haggitt / Kikuchi)Correa Cascade Staging Cotton Criteria (ERCP Complications)Crohn's Disease Activity Index (CDAI)Crohn's Disease Endoscopic Index of Severity (CDEIS)DeMeester Score (Reflux Monitoring)Distal Contractile Integral (DCI) Calculator Dukes / Modified Astler-Coller Staging (CRC)ERCP Post-Procedure Pancreatitis Risk Score ESD/EMR Curative Resection Criteria (Gastric)Eckardt Score (Achalasia)FODMAP Reintroduction Protocol Indicator Faecal Calprotectin Interpretation Faecal Incontinence Severity Index (FISI)Forrest Classification (Peptic Re-bleed Risk)Fukuoka Consensus Criteria (Pancreatic IPMN)Gastric Cancer TNM Staging (AJCC 8th)Gastric Emptying Scintigraphy Interpretation Glasgow-Blatchford Score (GBS)H. pylori Eradication Confirmation Algorithm Harmless Acute Pancreatitis Score (HAPS)Harvey-Bradshaw (HBI) to CDAI Conversion Harvey-Bradshaw Index (HBI)IBD Steroid Response Predictor (Oxford)IBS Rome IV Diagnostic Criteria IBS Symptom Severity Score (IBS-SSS)Integrated Relaxation Pressure (IRP) Interpreter JNET Classification (NBI Colonoscopy)Kudo Pit Pattern Classification Lichtiger Index (Modified Truelove & Witts)Los Angeles (LA) Classification (GORD)Lynch Syndrome Risk — Revised Bethesda Guidelines Lyon Consensus pH-Impedance Criteria (GORD)Lémann Index (Crohn's Digestive Damage)M-ANNHEIM Classification (Chronic Pancreatitis)MUST (Malnutrition Universal Screening Tool)Magnetic Resonance Index of Activity (MaRIA)Marsh Classification (Celiac Histopathology)Mayo Endoscopic Subscore (MES)Mayo Score (Ulcerative Colitis)Mirizzi Syndrome Classification (Csendes)Modified CT Severity Index (MCTSI)Montreal Classification (Crohn's Disease)Montreal Classification (Ulcerative Colitis)NICE Classification (NBI Polyp Lexicon)NOBLADS Score (Lower GI Bleeding)NRS-2002 (Nutritional Risk Screening)NSAID GI Risk Stratification (ACG/AGA)Nancy Histopathology Index (UC)Nutritional Risk Index (NRI)OLGA / OLGIM Staging (Gastric Gastritis)Oakland Score (Lower GI Bleeding)Oesophageal Cancer TNM Staging (AJCC 8th)Oxford Acute Severe Colitis Criteria (Travis)PREDICT Barrett's Risk Score Paris Classification (GI Lesion Morphology)Partial Mayo Score (UC)Prague C&M Classification (Barrett's)Ranson Criteria Robarts Histopathology Index (RHI)Rockall Score (Acute UGIB)Rutgeerts Score (Post-op Crohn's)SCCAI (Simple Clinical Colitis Activity Index)SIBO Breath Test Interpreter (Glucose/Lactulose)Serrated Lesion Classification (WHO 2019)Short Bowel Syndrome Classification (ESPEN)Siewert Classification (OGJ Tumours)Simple Endoscopic Score for Crohn's Disease (SES-CD)Strate Score (Diverticular Bleed)TPMT / NUDT15 Phenotype-to-Dose Adjustment Thiopurine Metabolite Interpreter Tokyo Guidelines 2018 (Cholangitis Severity)Tokyo Guidelines 2018 (Cholecystitis Severity)Truelove & Witts Criteria UCEIS (UC Endoscopic Index of Severity)Vienna Classification (Crohn's)Wexner (Cleveland Clinic) Constipation Score Wexner Faecal Incontinence Score (CCFIS)Zar Score (CDI Severity Predictor)

Mayo Score (UC)

Full Mayo Score — Ulcerative Colitis

4-domain severity assessment for UC. Remission= score ≤ 2 with no subscore > 1. Industry standard for clinical trial endpoints since 1987.

Stool Frequency

Rectal Bleeding

Endoscopic Subscore (Mayo Endoscopic Subscore)

Physician's Global Assessment

Guidelines & Evidence

Clinical Details

Section 1

When to Use

Global quantification of Ulcerative Colitis (UC) severity

Selecting patients for biological induction therapy (typically Score 6–12)

Standardized reporting of clinical and endoscopic endpoints in IBD research

To calculate the "Partial Mayo Score" when endoscopy is not available

Assay Selection

The Full Mayo score requires a lower endoscopy (Sigmoidoscopy or Colonoscopy). If endoscopy is skipped, use the "Partial Mayo Score" or "SCCAI."

Section 2

Formula & Logic

The 4 Domains (0–3 pts each)

Stool Frequency: Number of stools above baseline.

Rectal Bleeding: Frequency and amount of blood.

Endoscopic Findings: Mucosal appearance (Normal to Ulcerative).

Physician Global Assessment (PGA): Based on the other 3 items + patient well-being.

Total Score Interpretation (0–12)

Score ≤ 2	Clinical Remission (with endoscopic subscore 0 or 1)
Score 3–5	Mild Activity
Score 6–10	Moderate Activity
Score 11–12	Severe / Fulminant Activity

Section 3

Pearls/Pitfalls

The "PGA" Controversy

The Physician Global Assessment (PGA) is often criticized for being subjective and potentially redundant. Many modern regulators (like the FDA) now prefer the "Mayo 2-item" score (Stool frequency + Rectal bleeding) or the "3-item" score (excluding PGA) to reduce clinician bias.

The Baseline Problem

Stool frequency is measured relative to the patient's "normal" baseline. If a patient normally has 3 stools/day, then 4/day is scored as 1 point. This requires careful history-taking to avoid over-scoring healthy variations.

Clinical Pearls

Endoscopic Remission (MES ≤ 1) is the most robust predictor of drug-induced mucosal healing

Rectal bleeding is the most "sensitive" sub-score for active distal disease; disappearance of blood is often the first sign of response

A 3-point decrease in the full score is typically required for clinical "response" in drug trials

Section 4

Next Steps

Management Decisions

Score 6-12: High-impact therapy required. Admit if > 10 or meeting Truelove & Witts systemic criteria.

Score ≤ 2: Success. Maintain therapy; monitor calprotectin.

Complementary UC Tools

Mayo Endoscopic Subscore (MES)

Partial Mayo Score (Non-endoscopic)

Truelove and Witts Criteria (ASUC)

SCCAI Index

Section 5

Evidence Appraisal

The Landmark Study

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):1625-9. The definitive establishment of the score.

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Section 6

Literature

Rochester Heritage

The "Mayo Score" was a collaborative effort by the Mayo Clinic gastroenterology staff to move UC management into the era of randomized controlled trials (RCTs). It remains the most recognized UC index globally, appearing in the majority of biological drug labels.

Last Comprehensive Review: 2026

Related Gastroenterology Tools

Glasgow-Blatchford Score

AIMS65 Score

Forrest Classification

Rockall Score

Ranson Criteria

BISAP Score

Harvey-Bradshaw Index

Crohn's Disease Activity Index

Mayo Score

Truelove & Witts Criteria

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