IBD Activity Score Calculator
Calculate Crohn's Disease Activity Index (CDAI) from symptoms, lab values, and physical exam findings. Classifies remission, mild, moderate, and severe disease.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
CDAI Score
58
Severity (0–3)
0
How to Use This Calculator
- Enter Liquid/Soft Stools Per Day and Abdominal Pain score (0–3).
- Enter General Well-Being score (0–4) and Extra-Intestinal Complications count (0–6).
- Enter Antidiarrheal Use, Abdominal Mass presence, Hematocrit, Sex, and current Weight.
- Enter Ideal Body Weight to complete the Crohn's Disease Activity Index (CDAI) calculation.
- Review the total IBD Activity Score to classify disease as remission, mild, moderate, or severe.
How the result changes with Hematocrit (%)
| Hematocrit (%) | CDAI Score | Severity (0–3) |
|---|---|---|
| 15 | 220 | 2 |
| 28 | 142 | 0 |
| 43 | 52 | 0 |
| 55 | 0 | 0 |
What each input means
- Liquid/Soft Stools per Day
- Average number of liquid or very soft stools per day over the past 7 days.
- Abdominal Pain
- Daily abdominal pain rating.
- General Well-Being
- Overall sense of well-being.
- Extra-Intestinal Complications (0–6)
- Count of: arthritis/arthralgia, iritis/uveitis, erythema nodosum, fistula, fever >37.8°C, other.
- Antidiarrheal Use
- Use of loperamide or opiates for diarrhea control.
- Abdominal Mass
- Abdominal mass on examination.
- Hematocrit (%)
- Current hematocrit. Compared to normal (47 male, 42 female).
- Sex (0=Male, 1=Female)
- Biological sex for hematocrit normal reference.
- Current Weight (kg)
- Current body weight in kilograms.
- Ideal Body Weight (kg)
- Standard/ideal body weight for height and sex.
What each result means
- CDAI Score
- Crohn's Disease Activity Index. <150 = remission, 150–219 = mild, 220–449 = moderate, ≥450 = severe.
- Severity (0–3)
- 0 = remission, 1 = mild, 2 = moderate, 3 = severe.
- Stool Component
- Contribution of liquid stool frequency to total CDAI.
- Pain Component
- Contribution of abdominal pain to total CDAI.
- Well-Being Component
- Contribution of general well-being to total CDAI.
- Hematocrit Component
- Contribution of hematocrit deviation to total CDAI.
- Target for 70-pt Response
- CDAI target for clinical response (≥70-point decrease).
- Target for 100-pt Response
- CDAI target for significant clinical response (≥100-point decrease).
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersLiquid/Soft Stools per Day = 2, Abdominal Pain = 0, General Well-Being = 0, Extra-Intestinal Complications (0–6) = 0 = 10 input(s) provided
- Calculate CDAI Score58 = 58
- Calculate SeveritySeverity = severity0 = 0
- Calculate Stool ComponentStool Component = liquidStools * 7 * 228 = 28
- Calculate Pain ComponentPain Component = abdominalPain * 7 * 50 = 0
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