About the Truelove and Witts Criteria for Severity of Ulcerative Colitis
An attack of ulcerative colitis is classed as severe by the Truelove and Witts criteria when a patient passes six or more bloody stools a day and shows at least one sign of systemic toxicity — a temperature above 37.8 °C, a pulse above 90 beats per minute, a haemoglobin below 10.5 g/dL, or an ESR above 30 mm/hour. That combination defines acute severe ulcerative colitis, a medical emergency that warrants hospital admission and intravenous corticosteroids. Fewer than four bloody stools a day with no systemic upset is a mild attack; anything between the two is moderate. The stool count alone does not make an attack severe — at least one systemic criterion must also be met.
Formula
Severe = (≥ 6 bloody stools/day) AND (≥ 1 of: temp > 37.8 °C, pulse > 90 bpm, Hb < 10.5 g/dL, ESR > 30 mm/h). Mild = (< 4 bloody stools/day) AND (no systemic criterion). Moderate = anything in between.- bloody stools/day
- Number of blood-stained bowel movements in 24 hours. ≥ 6 is required for a severe classification.
- temperature
- Severe if above 37.8 °C.
- pulse
- Severe contributor if above 90 bpm.
- haemoglobin
- Severe contributor if below 10.5 g/dL (105 g/L).
- ESR
- Severe contributor if above 30 mm/hour; CRP > 30 mg/L is a common modern surrogate.
- There is no additive score — this is a rule, not a sum. A patient meets the severe class or they do not.
- The systemic criteria are the discriminator. Six or more bloody stools with entirely normal observations and bloods is not, by the original definition, a severe attack.
- The original 1955 paper set the anaemia threshold at haemoglobin below 75% of normal; 10.5 g/dL is the figure carried into modern guideline usage.
Interpreting the result
A severe classification is the actionable one: it defines acute severe ulcerative colitis and mandates admission, intravenous corticosteroids, and a structured day-3 reassessment for rescue therapy. A mild attack is managed as an outpatient with optimised oral and topical 5-aminosalicylates. The moderate band is the one to watch — it is not a stable resting place, and patients can cross into the severe category within a day or two, so moderate attacks are managed actively and reassessed against these same criteria at every contact. Because the criteria classify a single point in time, they must be repeated rather than read once; a patient admitted as moderate who develops a fever and tachycardia overnight has become a severe presentation.
| Score | Band | What it means | Action |
|---|---|---|---|
| < 4 bloody stools/day, no systemic sign | Mild | Mild attack | Outpatient management with optimised oral and topical 5-ASA; confirm activity and healing with the Mayo score at review |
| Between mild and severe | Moderate | Moderate attack — can progress to severe within days | Manage actively, escalate therapy, arrange early review, and reassess against these criteria at each contact |
| ≥ 6 bloody stools/day + ≥ 1 systemic criterion | Severe | Acute severe ulcerative colitis — a medical emergency with real colectomy and mortality risk | Admit; intravenous corticosteroids; day-3 assessment for rescue therapy; involve surgery and give VTE prophylaxis |
What the Truelove & Witts Criteria needs (5 inputs)
- Bloody bowel movements per day
- The count of bloody stools in 24 hours. Six or more is the threshold that opens the door to a severe classification, but it is not sufficient by itself.
- Temperature above 37.8 °C
- Pyrexia — one of the four systemic toxicity criteria.
- Pulse above 90 bpm
- Tachycardia — a systemic toxicity criterion. A rate-limiting beta blocker can mask it.
- Haemoglobin below 10.5 g/dL (105 g/L)
- Anaemia — a systemic toxicity criterion.
- ESR above 30 mm/hour
- Raised inflammatory response — a systemic toxicity criterion. CRP above 30 mg/L is often substituted where ESR is unavailable, though that substitution is a modern convention rather than part of the original criteria.
What it returns
- Severity class
- Mild, moderate, or severe — a category, not a numeric total.
- Systemic criteria met
- How many of the four toxicity criteria (fever, tachycardia, anaemia, raised ESR) are present, which is what separates severe from moderate at high stool frequency.
How it is calculated
Truelove and Witts built the grades empirically from a 1955 controlled trial of cortisone in ulcerative colitis, sorting attacks into mild, moderate and severe so that treatment effect could be reported by severity. The severe grade combined a stool-frequency threshold with a short list of objective systemic markers — temperature, pulse, haemoglobin and ESR — precisely because bleeding frequency alone was an unreliable guide to how sick a patient actually was. The criteria have barely changed since, and they endure less because the specific cut-offs are magic numbers than because they gave a reproducible, bedside definition of the one clinical state — acute severe colitis — that must not be missed.
Facts & figures
| Criterion | Threshold for severe |
|---|---|
| Temperature | > 37.8 °C |
| Pulse | > 90 bpm |
| Haemoglobin | < 10.5 g/dL (105 g/L) |
| ESR | > 30 mm/hour (CRP > 30 mg/L often substituted) |
A severe classification needs six or more bloody stools per day AND at least one of these four. Stool frequency alone does not qualify.
| Day-3 finding | Implication |
|---|---|
| > 8 stools/day | Most will need colectomy on that admission |
| 3–8 stools/day AND CRP > 45 mg/L | Most will need colectomy on that admission |
These predictors are applied after three days of intravenous steroids to decide on rescue therapy — they refine management within a Truelove-and-Witts-defined severe attack rather than replacing the admission criteria themselves.
Evidence
Derivation — Truelove and Witts
1955A randomised controlled trial of cortisone versus placebo in ulcerative colitis, in which attacks were graded as mild, moderate or severe so that the treatment effect could be analysed by disease severity. The severe grade paired a bloody-stool-frequency threshold with objective systemic markers — temperature, pulse, haemoglobin and ESR — and it is this severity definition, rather than the trial's cortisone result, that has endured.
In the pre-immunosuppression era the severe grade carried a substantial mortality, and cortisone reduced it — establishing both that severe colitis is a distinct, dangerous clinical state and that it responds to corticosteroids, the two premises on which modern acute-severe-colitis management still rests.
Oxford day-3 criteria — Travis
1996 · n = 5151 consecutive episodes of severe ulcerative colitis (defined by the Truelove and Witts criteria) in 49 patients admitted to the John Radcliffe Hospital, Oxford, prospectively monitored across 36 clinical, laboratory and radiographic variables through intensive intravenous treatment.
After three days of treatment, patients with more than eight stools a day, or three to eight stools with a CRP above 45 mg/L, mostly required colectomy on that admission. Incomplete responders overall had roughly a 40% chance of colectomy and a 60% chance of continuing symptoms — the basis of the day-3 decision point now used to trigger rescue therapy.
UCEIS in Truelove-Witts-defined severe colitis — Corte
2015 · n = 8989 patients with acute severe ulcerative colitis defined by the Truelove and Witts criteria, all treated with intravenous hydrocortisone, with endoscopic severity scored by the UCEIS and outcomes of rescue therapy, colectomy and readmission recorded.
40% needed rescue therapy and 24% underwent colectomy. A UCEIS of 7 or 8 on admission identified patients who almost all went on to need infliximab or ciclosporin beyond steroids, showing that endoscopic severity adds prognostic information within a Truelove-and-Witts-severe attack.
How it compares
Truelove & Witts Criteria vs Simple Clinical Colitis Activity Index (SCCAI)
Use the Truelove and Witts criteria to decide who needs admitting for acute severe colitis, and the SCCAI to track outpatient activity over time — they answer different questions and are not interchangeable.
The Truelove and Witts criteria are a binary triage tool built around systemic toxicity: their whole purpose is to flag the severe attack that needs hospital and intravenous steroids. The SCCAI is a graded symptom index designed for repeated outpatient measurement, sensitive across the mild-to-moderate range where Truelove and Witts simply reads 'not severe'. A patient can have a rising SCCAI while remaining below the Truelove-Witts severe threshold, and that is exactly the outpatient escalation the SCCAI is meant to capture.
Truelove & Witts Criteria vs Mayo score (Disease Activity Index)
Truelove and Witts classifies an acute attack for the admission decision; the Mayo score quantifies activity and endoscopic healing for treatment monitoring and trials.
The Mayo score combines stool frequency, rectal bleeding, an endoscopy subscore and a physician's global assessment into a graded 0–12 total used to define response and remission, particularly in clinical trials. Truelove and Witts deliberately excludes endoscopy and produces a category rather than a number. In an acute severe presentation the Truelove-Witts classification drives immediate management, while the Mayo score is better suited to tracking how a patient responds afterwards.
Pearls & pitfalls
- Stool frequency alone never makes an attack severe. Six or more bloody stools a day must be accompanied by at least one systemic criterion; without one, the attack is moderate by the original definition.
- Tachycardia can be masked by beta blockers, and a normal pulse in a patient on one should not falsely reassure.
- ESR was the original inflammatory marker; CRP above 30 mg/L is commonly used in its place today, but that is a pragmatic substitution, not part of the validated criteria.
- The criteria classify a moment in time. Reassess daily — a moderate attack can become severe overnight, and an admitted severe attack is then judged by day-3 predictors, not by re-running these criteria.
- A severe classification is a prompt to exclude Clostridioides difficile and cytomegalovirus and to involve surgery early, not simply to start steroids and wait.
Critical actions
- Admit any patient meeting the severe criteria and start intravenous corticosteroids — acute severe ulcerative colitis carries a genuine risk of colectomy and of death.
- Set a defined day-3 assessment point using stool frequency and CRP (the Oxford criteria) to decide on rescue therapy with infliximab or ciclosporin before steroids are declared to have failed.
- Exclude Clostridioides difficile and cytomegalovirus infection before escalating immunosuppression.
- Involve colorectal surgery from admission rather than at the point of medical failure.
- Give venous thromboembolism prophylaxis — active colitis is strongly prothrombotic despite the rectal bleeding.
- Avoid antimotility agents, opioids and NSAIDs, all of which raise the risk of colonic dilatation.
Why this score exists
Truelove and Witts were reporting a therapeutic trial, not designing a severity index for its own sake — the grading existed so that cortisone's effect could be examined separately in mild, moderate and severe disease. That origin explains the criteria's shape: the systemic markers were chosen because they were objective, cheap and reproducible in 1955, and the severe grade was drawn where it was because that was the group in whom outcomes, and the treatment effect, were most consequential. The criteria have survived seven decades of therapeutic change largely unaltered because they answer a question that has not changed — which patient in front of you right now has a colitis attack dangerous enough to admit.
About the creator
First author, 1955 cortisone trial
Graded attacks of ulcerative colitis as mild, moderate or severe so that cortisone's effect could be analysed by severity — the grading, not the trial result, is what endured.
Senior author
Co-authored the trial from which the severity criteria are taken.
Limitations
- The criteria classify severity at a single point in time and say nothing about response to treatment — that is why the separate Oxford day-3 predictors exist.
- They rely on ESR, which is slower and less specific than CRP; the CRP substitution used in practice has not been formally incorporated into the original definition.
- Anaemia and a raised inflammatory response can have causes other than colitis, so a systemic criterion is not always attributable to the flare.
- They do not include endoscopic appearance, which carries independent prognostic weight in acute severe colitis (captured instead by the UCEIS).
- As a binary severe/not-severe instrument, they are insensitive to change across the mild-to-moderate range, where a graded index is more useful for monitoring.
If you are the patient
The Truelove and Witts criteria are a quick check doctors use to decide how serious a flare-up of ulcerative colitis is, and in particular whether someone needs to be admitted to hospital. A flare counts as 'severe' when a person is passing six or more bloody stools a day and also has at least one sign that the whole body is affected — a raised temperature, a fast heart rate, a low blood count, or a raised inflammation marker in the blood. A severe flare is treated as an emergency, usually with steroids given into a vein in hospital, because it can be dangerous if left. Milder flares can often be treated at home with tablets and enemas. Because a flare can get worse quickly, doctors repeat this check regularly rather than relying on a single assessment.
Frequently asked questions
What defines acute severe ulcerative colitis?#
Six or more bloody stools a day plus at least one systemic sign of toxicity — a temperature above 37.8 °C, a pulse above 90 bpm, a haemoglobin below 10.5 g/dL, or an ESR above 30 mm/hour. This is the Truelove and Witts definition, and it mandates hospital admission and intravenous steroids.
Does a high stool count alone make an attack severe?#
No. Six or more bloody stools a day is necessary but not sufficient — at least one of the four systemic criteria must also be present. Frequent stools with entirely normal observations and bloods is classed as a moderate attack.
Can CRP be used instead of ESR?#
In practice, yes — a CRP above 30 mg/L is commonly substituted where ESR is unavailable or slow to result. It is a pragmatic modern convention, though the original 1955 criteria specified ESR.
What happens after a patient is admitted with severe colitis?#
They receive intravenous corticosteroids and are reassessed at day 3 using the Oxford criteria — more than eight stools a day, or three to eight stools with a CRP above 45 mg/L, identifies those who will most likely need rescue therapy with infliximab or ciclosporin, or colectomy.
Are the Truelove and Witts criteria still used?#
Yes. Despite dating from 1955, they remain the definition of acute severe ulcerative colitis in current British, European and American guidelines, because they give a reproducible bedside answer to which patient needs admitting.
How many bloody stools per day define a severe attack?#
Six or more, and that criterion is mandatory rather than one of a list. In addition, at least one systemic marker must be present: a pulse above 90 beats per minute, a temperature above 37.8 degrees Celsius, haemoglobin below 10.5 g/dL, or an ESR above 30 mm/hour. Six bloody stools alone without any systemic disturbance does not meet the definition.
What happens on day 3 of admission for acute severe colitis?#
Day 3 is the formal decision point, assessed with the Oxford (Travis) criteria: more than eight stools per day, or three to eight stools with a CRP above 45 mg/L, predicts a high likelihood of needing colectomy during that admission. Reaching that threshold is the trigger to start rescue therapy with infliximab or ciclosporin and to involve colorectal surgery, rather than continuing corticosteroids and reassessing later.
Do the Truelove and Witts criteria apply to Crohn's colitis?#
They were derived and validated in ulcerative colitis and are not formally validated in Crohn's disease. In practice a patient with severe Crohn's colitis presenting with frequent bloody stools and systemic upset is managed along very similar lines, including the same urgency about rescue therapy and surgical involvement. But the criteria should be described as being applied by analogy rather than quoted as a validated assessment in that setting.
References
Original / primary reference
Validation and prognosis
- Travis SPL, Farrant JM, Ricketts C, et al. Predicting outcome in severe ulcerative colitis. Gut. 1996;38(6):905-910.
- Corte C, Fernandopulle N, Catuneanu AM, et al. Association between the ulcerative colitis endoscopic index of severity (UCEIS) and outcomes in acute severe ulcerative colitis. J Crohns Colitis. 2015;9(5):376-381.
Guidelines
- Lamb CA, Kennedy NA, Raine T, et al. British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults. Gut. 2019;68(Suppl 3):s1-s106.
- Rubin DT, Ananthakrishnan AN, Siegel CA, et al. ACG Clinical Guideline: Ulcerative Colitis in Adults. Am J Gastroenterol. 2019;114(3):384-413.