Modified Truelove and Witts criteria
| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| Bloody stool per day, n | <4 | 4–6 | >6 |
| Pulse, beats per minute | <90 | ≤90 | >90 |
| Temperature,°C | <37.5 | 37.5–37.8 | >37.8 |
| Haemoglobin, g/dL | >11.5 | 11.5–10.5 | <10.5 |
| ESR, mm/h (or CRP, mg/L) | <20 (normal) | 20–30 (<30) | >30 (>30) |
CRP = C-reactive protein; ESR = erythrocyte sedimentation rate.