Settle
How to Read the Bristol Stool Chart (All 7 Types)
The Bristol Stool Chart is one of the simplest health tools you're not using. It turns a vague, awkward question — 'is this normal?' — into a clear, seven-point scale that you and your doctor can actually talk about.
Here's how to read it, what each type suggests about your digestion, and how to put it to work day to day.
What the Bristol Stool Chart is
Developed at the University of Bristol in the 1990s, the Bristol Stool Chart (also called the Bristol Stool Scale) classifies human stool into seven types based on shape and consistency. It was designed as a research and clinical tool, and it's now used worldwide because it gives everyone a shared vocabulary.
The core idea is simple: consistency reflects how long stool spent in your colon. The longer it sits, the more water is absorbed and the harder it gets. The faster it moves, the softer and looser it is.
The 7 types, explained
From hardest to loosest, here's what each type looks like and what it generally indicates:
- Type 1 — Separate hard lumps, like nuts. Hard to pass. Suggests constipation.
- Type 2 — Lumpy and sausage-shaped. Still a sign of constipation.
- Type 3 — A sausage with cracks on the surface. Healthy and normal.
- Type 4 — Smooth and soft, like a snake. The ideal type for most people.
- Type 5 — Soft blobs with clear-cut edges. Trending toward loose; may mean a lack of fiber.
- Type 6 — Mushy, ragged edges. A sign of mild diarrhea or fast transit.
- Type 7 — Entirely liquid, no solid pieces. Diarrhea.
What your type says about your health
Types 3 and 4 are the sweet spot — formed, soft, and easy to pass. If you're consistently there, your hydration, fiber, and transit time are likely in a good range.
Types 1 and 2 point to constipation and stool moving too slowly. More water, fiber, and movement often help. Types 5 through 7 point the other way — stool moving too fast, toward diarrhea — which can be tied to diet, stress, infection, or an underlying condition.
One-off changes are normal and usually reflect what you ate or how you slept. It's the repeated pattern that matters. Persistent changes, blood, or severe symptoms are worth raising with a healthcare professional.
How to track your Bristol type
The chart is only useful if you actually use it. The easiest approach is to log your type each time alongside a few notes — what you ate, your stress, your sleep — so patterns can emerge over weeks.
That's exactly what the Settle app is built for: tap your Bristol type in a couple of seconds, and it connects your entries into trends you can act on and share with your doctor.