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IBD Tools

Work out the scores your inflammatory bowel disease (IBD) team uses, with the units on your own lab report. Nothing you enter leaves your device.

These tools help you understand and prepare the scores IBD teams use to describe how active Crohn’s disease or ulcerative colitis is. Gastroenterologists use them to track how things are going, and in some countries a specialist needs one to apply for funded treatment. Your IBD team’s score is the one that counts: these tools explain the numbers, they don’t diagnose anything or tell you what treatment to have.

The calculators are grouped below by condition and age, and each shows what you’ll need to fill it in.

They run entirely in your browser. Nothing you type is sent anywhere, and nothing is saved unless you tick “Allow saving on this device”, and then only in your browser on that device, never online. You can keep dated results to compare later, and lock them if you want.

Activity scores

Scores IBD teams use to describe how active the disease is. Not sure which one? Your IBD team can tell you which they use, and each page says how your country’s medicines rules use it.

Crohn’s disease

For adults

  • CDAI Calculator

    The score many gastroenterologists use for Crohn’s disease in adults, worked out from a week of symptoms, one blood test and your weight.

    You’ll need: a 7-day symptom diary, a blood test (haematocrit), your weight, a standard weight from your IBD team and an examination by your doctor.

    Used in medicines rules in Australia, New Zealand and the UK.

  • HBI Calculator

    A quick Crohn’s disease score from one day’s symptoms, used by IBD teams and in some medicines funding rules.

    You’ll need: yesterday’s symptoms and an examination by your doctor.

    Used in medicines rules in Canada, New Zealand and the UK.

  • CDAI-PRO2 Calculator

    Two items from the CDAI that you report yourself, stools and tummy pain over a week, used in many trials of new Crohn’s medicines.

    You’ll need: a 7-day symptom diary only.

For children and teenagers

  • PCDAI Calculator

    The score children’s IBD teams use for Crohn’s disease, worked out from the last week, recent blood tests, growth and an examination.

    You’ll need: last week’s symptoms, blood tests (haematocrit, ESR, albumin), your child’s growth chart and an examination by the IBD team.

    Used in medicines rules in Australia and New Zealand.

  • wPCDAI Calculator

    A shorter, reweighted version of the PCDAI that many children’s IBD teams use, without the height, haematocrit or tummy examination items.

    You’ll need: last week’s symptoms, blood tests (ESR, albumin), recent weight changes and an examination by the IBD team.

Ulcerative colitis

For adults

  • Partial Mayo Score Calculator

    The ulcerative colitis score built from stool frequency, rectal bleeding and your doctor’s overall assessment, without a colonoscopy.

    You’ll need: how often you go to the toilet compared with normal, any bleeding on your worst day and your doctor’s overall assessment.

    Used in medicines rules in Australia and Canada.

  • SCCAI Calculator

    A score for ulcerative colitis made entirely from symptoms you report: bowel movements, urgency, bleeding, wellbeing and problems outside the gut.

    You’ll need: your symptoms only.

    Used in medicines rules in New Zealand.

For children and teenagers

  • PUCAI Calculator

    The ulcerative colitis score children’s IBD teams use, made from six things a parent or young person can report.

    You’ll need: your child’s symptoms only.

    Used in medicines rules in Australia and New Zealand.

Other scores and tests explained

These pages explain a score or test that has no calculator here.

  • Faecal Calprotectin Test

    What the faecal calprotectin stool test measures, why doctors use it, and how to read the number on your result.

    Useful to have: your test result.

  • The Montreal Classification

    What codes such as A2 L3 B1 or E2 in a clinic letter mean: the standard way IBD teams record the type of Crohn’s disease or ulcerative colitis.

    Useful to have: your clinic letter.

  • The Full Mayo Score

    How the full Mayo score adds what the doctor sees at colonoscopy to the partial Mayo score, and how the modified Mayo score used in newer trials differs.

    Useful to have: a colonoscopy report.

  • Acute Severe Ulcerative Colitis (Truelove and Witts)

    What acute severe ulcerative colitis means, the criteria doctors use to recognise it, and why it is treated in hospital.

    Useful to have: hospital blood test results.

Saved results in this browser

The tools save nothing unless you tick “Allow saving on this device” on a tool. Saved results stay in this browser only: another browser on this device shows nothing. “Delete all saved results” removes everything any tool has saved in this browser, and the lock if there is one.