Histological activity index used in trials.
Histological activity in ulcerative colitis, developed for clinical trials from the items of the Geboes score and modified Riley score with the best measured reliability.
The calculator collects 4 items:
Any item left blank stops the score being calculated — an incomplete form never reports as remission.
| ≤ 3, no neutrophils/ulcers | Histological remission |
| otherwise | Histologically active |
Bands as implemented in IBD Care. A band is a description of the score, not an instruction.
Developed as a trial instrument, and its operating properties outside trials are less well established. Like the Nancy index it needs structured pathology reporting and is subject to sampling. Scores are not interchangeable with the Nancy index or the Geboes score.
Content last reviewed 2026-10-10. References were resolved against PubMed, a service of the US National Library of Medicine, which does not endorse this site.
Robarts Histopathology Index is implemented as an interactive calculator in IBD Care, with its full guidance and scoring bands.
Open IBD Care