Select the symptom severity in each category to visualize the cumulative Partial Mayo Index.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Rapid assessment of Ulcerative Colitis (UC) activity in the outpatient setting
Symptomatic monitoring between endoscopic procedures
To screen patients for clinical response in everyday practice
Philosophy of the Partial Score
The Partial Mayo Score utilizes only the three non-invasive components of the Full Mayo. It correlates highly with the absolute score and provided a validated way to track disease without repeated sigmoidoscopy.
Section 2
Formula & Logic
The 3 Clinical Components (0–9 pts total)
01
Stool Frequency: Relative to baseline (0–3).
02
Rectal Bleeding: Most severe of the day (0–3).
03
Physician Global Assessment: Based on current status and patient reports (0–3).
Score Interpretation
0–1 Points
Clinical Remission
2–4 Points
Mild Activity
5–6 Points
Moderate Activity
7–9 Points
Severe Activity
Section 3
Pearls/Pitfalls
The "Invisible" Inflammation
While the Partial Mayo score is excellent for symptoms, it can underestimate disease in 10-15% of patients who have persistent endoscopic inflammation despite normalization of bowel habits. This is why "Treat-to-target" requires periodic objective markers (Calprotectin or Endoscopy).
Clinically Meaningful Change
A reduction of ≥ 2 points in the Partial Mayo score is generally accepted as the threshold for a "Clinical Response" in clinical trials.
Clinical Pearls
Physician Global Assessment (PGA) includes the patient's functional capacity and systemic well-being
Rectal bleeding is the most specific component for distal UC activity
If the score is > 6, the patient likely requires a change in maintenance therapy or escalation to biologicals
Section 4
Next Steps
Management Decisions
01
Remission (0-1): Success. Long-term maintenance and annual screening.
02
Moderate to Severe (> 4): Perform sigmoidoscopy to calculate Full Mayo and confirm mucosal activity.
Complementary UC Tools
Full Mayo Score (with Endoscopy)
SCCAI (Simple Clinical Colitis Activity Index)
Truelove and Witts (ASUC)
Section 5
Evidence Appraisal
The Foundational Score
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 source of the components.
