Experts have proposed updated diagnostic criteria for acute severe ulcerative colitis (ASUC) that reflect today’s treatment landscape, replacing reliance on the 1955 Truelove and Witts criteria with a broader assessment of symptoms, laboratory findings, and endoscopic findings. The new recommendations are intended to help physicians identify severe disease in patients already receiving corticosteroids or advanced therapies, whose illness may be missed by the traditional criteria.
The recommendations were developed by an international panel of inflammatory bowel disease (IBD) experts and published in Clinical Gastroenterology and Hepatology. The group reached consensus through a four-round modified Delphi process involving specialists from Europe, North America, and the Asia-Pacific region.
ASUC is a life-threatening flare of ulcerative colitis that often requires hospitalization and prompt treatment. Delayed diagnosis can increase the risk for toxic megacolon, colectomy, and death. Although the Truelove and Witts criteria have been the standard for 71 years, they may not fully reflect how modern therapies alter the clinical presentation of severe disease.
Senior author Peter D.R. Higgins, MD, PhD, MSc, director of the IBD program in the department of medicine at the University of Michigan, Ann Arbor, explained why updated criteria are needed.
“The old criteria were from before we routinely used steroids and advanced therapies,” Dr. Higgins told GI & Hepatology News. “Most of our patients admitted for ASUC now are on both steroids and an advanced therapy (e.g. prednisone 40 mg and an infliximab infusion last week) — so they ‘look’ less sick, but they are actually much sicker than the patients with ASUC in 1955, when Truelove and Witts criteria were developed.”
To update the criteria, the investigators assembled a panel of 12 internationally recognized gastroenterologists between April 2024 and September 2025. Using a four-round modified Delphi process, the experts evaluated 164 statements on symptoms, laboratory tests, endoscopic findings, imaging, and diagnostic pathways. Three co-chairs guided the discussions but did not vote, and agreement required support from at least 70% of the panel. A virtual meeting after the third round helped refine the proposed criteria before the final vote.
The panel agreed that updated diagnostic criteria are needed because the current framework no longer reflects modern clinical practice. Ninety-two percent of experts supported replacing or supplementing the existing criteria. They also agreed that diagnosis should be based on a combination of required “major” criteria and supporting “minor” criteria, which strengthen the diagnosis but are not sufficient on their own.
For patients already receiving advanced therapy or low-dose corticosteroids as outpatients, the panel recommended diagnosing ASUC when at least two of three major criteria are present along with at least two minor criteria. The major criteria are a C-reactive protein (CRP) level at least twice the upper limit of normal, six or more bowel movements in 24 hours, and visible blood in at least half of bowel movements over 24 hours. Minor criteria include low albumin, tachycardia, nocturnal bowel movements, anemia, fever, and an elevated white blood cell count. The panel emphasized that even all three major criteria are not enough on their own without supporting minor findings.
The recommendations are different for patients already taking high-dose corticosteroids before hospitalization because these drugs can reduce inflammation and mask the severity of disease. For these patients, the panel recommended lower diagnostic thresholds. All three major criteria alone are considered sufficient, using a CRP level at or above the upper limit of normal instead of twice the upper limit, and visible blood in at least one-third rather than one-half of bowel movements. Alternatively, the diagnosis can be made when two major criteria are present along with at least two minor criteria.
The panel did not reach consensus on diagnostic criteria for patients who had not yet received treatment. The approach with the most support combined an elevated CRP level with either frequent bowel movements or visible bleeding, plus at least two minor criteria, but only 64% of experts agreed, short of the 70% threshold for consensus. The investigators said previously untreated patients are a more diverse group and often need additional testing to rule out infectious colitis and other conditions before ASUC can be confirmed.
AbbVie funded the study. Dr. Higgins and many coauthors reported consulting, speaking, research, or advisory relationships with multiple pharmaceutical companies.
Expert Insight
GI & Hepatology News invited Dr. Higgins to elaborate on the recommendations.
How do you expect these new criteria to change the evaluation of patients who present with suspected ASUC after already receiving outpatient corticosteroids or advanced therapy?
Dr. Higgins: We should take into account the therapies that people’s UC has essentially blown through, and at least mentally account for the 40 mg prednisone and 700 mg of Remicade [infliximab] they got last week. This is still ASUC even though they are only having 4 bloody bowel movements per day and their CRP is 23 mg/L
What do you see as the biggest challenges to implementing these proposed criteria in routine clinical practice, particularly in community hospitals or centers with limited access to urgent endoscopy?
Dr. Higgins: The Truelove and Witts criteria have been around and taught for decades. And it is hard to unlearn things.
Because the panel did not reach consensus on diagnostic criteria for untreated patients, how should physicians approach these patients while awaiting prospective validation of the new criteria?
Dr. Higgins: For truly untreated patients (pretty uncommon in 2026), the old criteria should still work.
Is there anything else you’d like to say about this work?
Dr. Higgins: We need to recognize that ASUC today (after failing multiple therapies) is much less likely to respond to IV steroid monotherapy than the patients of 1955, or even 2005.
We need to recognize these refractory patients and consider using advanced therapy (with intravenous corticosteroids as co-therapy) as first line agents when hospitalized.
This can be complicated, as it adds costs to the hospitalization that may not be covered by the diagnosis-related group payment, especially for expensive on-patent drugs.