REFINED-ASUC Rethinking How We Diagnose Acute Severe UC: CGH | August 2026

Introduction:

Acute severe ulcerative colitis (ASUC) is still commonly diagnosed using the 1955 Truelove and Witts criteria. However, these criteria were developed long before corticosteroids, biologics, and small-molecule therapies became routine. The REFINED-ASUC international Delphi consensus proposes a modern diagnostic framework, particularly for patients who deteriorate despite already receiving outpatient therapy.

Why was this consensus needed?

Truelove and Witts criteria are more than 70 years old.

They do not account for prior corticosteroid or advanced therapy exposure.

Modern treatment may modify inflammatory and clinical manifestations of severe disease.

Delayed recognition of ASUC can delay hospitalisation, rescue therapy, and surgical assessment.

Key Takeaways:

For patients already receiving advanced therapy or corticosteroids, ASUC can be considered when all 3 major criteria + ≥2 minor criteria are present.

Major criteria: CRP ≥2× ULN, ≥6 bowel movements/24 h, and visible blood in ≥50% of bowel movements.

Minor criteria: low albumin, tachycardia, nocturnal bowel movements, low hemoglobin, fever, or elevated leukocyte count.

Patients already receiving high-dose corticosteroids require lower thresholds: CRP ≥1× ULN and visible blood in ≥33% of bowel movements.

Similar principles were considered for untreated patients, but formal consensus was not achieved.

Endoscopic assessment should support the diagnosis and evaluate disease severity.

CMV infection should be excluded during endoscopic assessment.

Imaging should be performed when appropriate to exclude toxic megacolon.

These proposed criteria require prospective validation before replacing established diagnostic standards.

What’s New?

Unlike Truelove and Witts, REFINED-ASUC explicitly incorporates current treatment exposure and recognises that corticosteroids and advanced therapies can modify the clinical presentation of ASUC.

Bottom Line:

REFINED-ASUC proposes treatment-adjusted diagnostic criteria for severe UC in the modern therapeutic era. The framework is clinically relevant, particularly for patients already receiving corticosteroids or advanced therapy, but requires prospective validation before replacing Truelove and Witts criteria.