The Bristol stool chart, explained

A short guide · Updated September 24, 2026

The Bristol Stool Form Scale is a chart of seven stool shapes. It was developed at the Bristol Royal Infirmary in England in the 1990s so that people and doctors could describe stool the same way, without guessing at words. Researchers found that stool shape tracks how long food takes to pass through the gut more closely than how often you go.

The seven types

• Type 1 — Separate hard lumps
  Harder
• Type 2 — Lumpy sausage
  Harder
• Type 3 — Sausage with cracks
  In the middle
• Type 4 — Smooth, soft sausage
  In the middle
• Type 5 — Soft blobs with clear edges
  In the middle
• Type 6 — Mushy, ragged pieces
  Looser
• Type 7 — Watery, no solid pieces
  Looser

Types 1–2 are harder, 6–7 are looser, and 3–5 are in between. Most people see a mix over a week, and a single day says little on its own.

How often is usual?

The range is wider than you might think. In a large US health survey, about 96% of adults who described their bowel habits as typical went somewhere between three times a day and three times a week. Everyone's normal is different — which is why it helps to know yours. More on how often is normal.

Why notice your own pattern

When you know what's usual for you — how often, and which shapes — a change is easier to notice and easier to describe. "Mostly type 4, once a day, and for the last two weeks mostly type 6" is clearer than "things feel off." That's useful if you ever talk to a doctor about it.

When to talk to a doctor

Blood in your stool, black or tarry stools, pale stools that last more than a few days, a change in your bowel habits that doesn't go away, or ongoing belly pain are worth checking with a healthcare professional. Many causes are not serious, but only a clinician can tell. Get emergency care for heavy bleeding, or bleeding with dizziness, fainting or trouble breathing. A log is not a substitute for recommended screening.

Keeping track, privately

Porcelain is a poop log for iPhone built around this chart: tap a shape to save, and after 7 logged days you'll see your usual pattern. No account, no ads, and your logs stay on your iPhone. See how it works.

This guide is general information, not medical advice. Porcelain is for personal record-keeping and is not intended to diagnose or treat any condition. Check with a doctor before making medical decisions.

Sources

1. Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scandinavian Journal of Gastroenterology, 1997. PubMed
2. Mitsuhashi S, et al. Characterizing normal bowel frequency and consistency in a representative sample of adults in the United States (NHANES). American Journal of Gastroenterology, 2018. PubMed
3. Centers for Disease Control and Prevention. Symptoms of colorectal cancer. cdc.gov