Bristol Stool Chart Interpreter
The Bristol Stool Chart is the seven-type scale clinicians use to classify stool form — a quick, surprisingly informative window into gut transit time. Pick the type that best matches what you typically see, and get a plain-language read on what it usually means.
Think about your most typical pattern, not a one-off
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How it works
What the chart measures
Developed at the Bristol Royal Infirmary in the 1990s, the chart classifies stool form into seven types as a practical proxy for whole-gut transit time — longer transit produces harder forms (Types 1–2), faster transit produces looser forms (Types 5–7). It requires no lab, no app, and no tracking spreadsheet, which is exactly why it has survived as a clinical standard.
Typical vs ideal
Types 3 and 4 are generally considered typical healthy forms. But gut transit varies with diet, hydration, stress, travel, and hormones — a week of Type 2 on a work trip is not a disease. Patterns over weeks matter more than any single observation.
When to stop interpreting and call someone
This chart describes form, not cause. Persistent change lasting more than a few weeks, blood or black stool, unintentional weight loss, fever, or severe pain are not calculator questions — they are reasons to see a clinician promptly.
Frequently asked questions
What is the Bristol Stool Chart?
A seven-type visual scale developed at the Bristol Royal Infirmary and published in 1997. Clinicians use it worldwide as a quick proxy for intestinal transit time — Types 1–2 suggest slow transit, 3–4 are typical, and 5–7 suggest fast transit.
Which Bristol type is healthiest?
Types 3 and 4 are generally considered typical healthy forms. Occasional variation toward 2 or 5 is normal and usually reflects short-term changes in diet, hydration, or routine.
Should I track my type every day?
No — the chart is most useful as a pattern check over weeks, not a daily log. If you notice a persistent shift from your usual pattern, that trend is the signal worth acting on.
When should I see a doctor about stool changes?
Promptly, if you notice blood or black stool, unintentional weight loss, fever, severe pain, or a persistent change lasting more than a few weeks. The chart helps describe what you see; it cannot explain why.
Is the Bristol chart a diagnostic tool?
No. It is a standardized description scale — a shared vocabulary between you and a clinician. It does not diagnose any condition, and neither does this page.
Sources
- Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol, 1997.
- Heaton KW, Radvan J, Cripps H, et al. Defecation frequency and timing, and stool form in the general population: a prospective study. Gut, 1992.
This calculator is for informational purposes only and is not medical advice, diagnosis, or treatment. Reference ranges are general population guidelines — always discuss your lab results with a qualified healthcare professional.