Truelove & Witts Severity Calculator

About this calculator

The Truelove & Witts index, published in 1955, was the first standardized way to grade ulcerative colitis severity and is still the basis for the “mild/moderate/severe” categories used in clinical practice today. It classifies severity from six criteria: stool frequency, visible blood in stool, fever, heart rate, hemoglobin (anemia), and ESR (erythrocyte sedimentation rate, a marker of inflammation).

Meeting all six “mild” thresholds — under 4 stools a day, no fever, normal pulse — classifies as mild disease; meeting all six “severe” thresholds — 6 or more bloody stools a day, fever, tachycardia, significant anemia, elevated ESR — classifies as severe, with everything in between graded moderate.

Gastroenterologists use severity grading like this to decide whether a flare can be managed as an outpatient or needs hospital admission for IV steroids, and it remains a reference point that later scores (like the Mayo score) were built to refine. This tool is for reference only, not medical advice.