IBS Severity Score (IBS-SSS) Calculator
Score your IBS out of 500 with the scale used in clinical trials.
- Free
- About 2 minutes
- No account
- Updated October 3, 2026
The short answer
The IBS Symptom Severity Score (IBS-SSS) rates five things out of 100 each: pain severity, how many days you had pain in the last 10, bloating severity, how unhappy you are with your bowel habit, and how much IBS interferes with your life. The total runs from 0 to 500. Under 75 is in the range of people without active IBS, 75 to 174 is mild, 175 to 299 moderate and 300 or more severe.
How to use the IBS Severity Score Calculator
- 1Answer whether you have pain and bloating right now, and if so how severe, on a 0 to 100 slider.
- 2Enter how many of the last 10 days you had pain.
- 3Rate how unhappy you are with your bowel habit and how much IBS interferes with your life.
- 4Get your total out of 500, your severity band and the item that contributes most.
How the IBS-SSS is scored
The IBS Symptom Severity Score was published in 1997 by Francis, Morris and Whorwell as a simple way to monitor IBS and its progress. It has become one of the most used outcome measures in IBS research, including trials of the low FODMAP diet and gut-directed hypnotherapy.
Each of the five items is worth up to 100 points. If you do not have pain, both pain items score 0; if you do not have bloating, the bloating item scores 0.
| Item | How it is scored | Points |
|---|---|---|
| Pain severity | Slider from no pain to very severe | 0 to 100 |
| Pain frequency | Days with pain in the last 10, times 10 | 0 to 100 |
| Bloating severity | Slider from none to very severe | 0 to 100 |
| Bowel habit | Slider from very satisfied to very unhappy | 0 to 100 |
| Life interference | Slider from not at all to completely | 0 to 100 |
What your score means
The bands come from the original paper. They describe how much your symptoms are affecting you, which is what most treatment decisions are actually about.
| Total | Band |
|---|---|
| 0 to 74 | In the range of people without active IBS |
| 75 to 174 | Mild |
| 175 to 299 | Moderate |
| 300 to 500 | Severe |
What the score cannot tell you
It does not diagnose IBS. Coeliac disease, inflammatory bowel disease, bile acid diarrhoea and other conditions can produce the same symptoms and the same score. A diagnosis needs a clinician, usually with a few blood and stool tests.
It is also a snapshot. IBS comes and goes, so one score in a bad week and one in a good week can be hundreds of points apart. The trend over several scores tells you far more than any single one.
Frequently asked questions
- What is a normal IBS-SSS score?
- A total under 75 is in the range the scale's authors found in people without active IBS. Between 75 and 174 counts as mild, 175 to 299 as moderate and 300 or more as severe.
- What IBS-SSS change counts as an improvement?
- In the original 1997 study, a fall of about 50 points was associated with a clinical improvement, and many trials use a 50-point drop to define a responder.
- Can the IBS-SSS diagnose IBS?
- No. It measures how severe your symptoms are, not what causes them. IBS is diagnosed by a clinician from your symptom pattern, usually with blood tests and a stool test to rule out other conditions.
- How often should I take the IBS severity score?
- Every two to four weeks is a sensible rhythm, or before and after any change you are testing, such as a low FODMAP elimination phase. Because IBS fluctuates, the trend matters more than any single result.
- Why does the IBS-SSS ask about the last 10 days?
- The pain frequency item counts days with pain in the last 10 and multiplies by 10, so it scores out of 100 like the other items. It keeps the questionnaire anchored to recent symptoms rather than a vague overall impression.
- Is my result stored?
- Your answers are used to calculate the result and email it to you. The tool does not create an account or save your answers to a medical record.
Read more
- How Do I Know if My IBS Is Flaring Up?
There is no blood test for an IBS flare, so the answer is a comparison with your own baseline. How to define one, measure it, and tell it from something else.
- How Long Does an IBS Flare Up Last? Honest Answer
No study has measured how long an IBS flare lasts, because nobody agreed a definition. What the evidence does show, and what actually decides your duration.
- How to Explain IBS to Your Doctor in 60 Seconds
IBS is diagnosed from what you say, not from a test. The exact words that get you a positive diagnosis, the right tests, and a doctor who keeps listening.
- Does Gut-Directed Hypnotherapy Work for IBS?
Gut-directed hypnotherapy helps a real minority of people with IBS. The trials, the response rates, and why the 70 to 80% figure everyone quotes is misread.
Sources
- Francis CY, Morris J, Whorwell PJ. The irritable bowel severity scoring system: a simple method of monitoring irritable bowel syndrome and its progress. Aliment Pharmacol Ther. 1997;11(2):395-402. doi:10.1046/j.1365-2036.1997.142318000.x
Cite this tool
Clairop. IBS Severity Score Calculator. www.clairop.com/tools/ibs-severity-score. Updated October 3, 2026.
Clairop is a general wellness app for people living with a diagnosed digestive condition. It does not replace professional medical care, diagnosis, or treatment. Always follow your healthcare provider's advice.
Clairop logs meals, symptoms and stool in seconds, then looks for the foods your gut reacts to, including reactions that land days later.
More free tools
- Free toolIBS Type CalculatorWork out your Rome IV IBS subtype from your Bristol stool counts.Use it free →
- Free toolRome IV IBS Criteria CheckerSee whether your symptoms fit the Rome IV pattern for IBS.Use it free →
- Free toolLow FODMAP Reintroduction PlannerTurn the reintroduction phase into dated challenges you can follow.Use it free →