The Bristol Stool Chart (or Bristol Stool Form Scale) is how doctors describe poo. It sorts stools into seven types by shape and texture — from hard lumps to liquid. Types 3 and 4 are the healthy target; Types 1–2 point to constipation and Types 6–7 to diarrhoea.
Stool has spent a long time in the colon and lost water. Increase fluids (at least 1.5 litres a day), add fruit and vegetables gradually, and try a footstool to raise your knees.
A little slow. Regular meals, fluids, gentle activity and not ignoring the urge usually help.
A healthy, well-formed stool. Keep doing what you are doing.
The ideal stool — soft, smooth and easy to pass. Royal approval granted. 👑
On the soft side. Often a sign you could use a little more fibre from fruit, veg and wholegrains.
Moving through quickly. Sip fluids, note any triggers (caffeine, alcohol, spicy food) and see how the next few go.
Watery stool loses fluid and salts fast. Drink plenty, consider oral rehydration solution, and seek advice if it lasts more than a few days or you see blood.
A healthy stool is usually Type 3 or 4: sausage-shaped, soft, easy to pass without straining, and medium to dark brown. Everyone is a little different, so the most useful thing is to learn your normal — and notice when it changes. Check what different colours mean in our poo colour chart.
Stool type mostly reflects transit time — how long waste spends in the colon. The longer it stays, the more water is absorbed and the harder it gets (Types 1–2). Moving too fast leaves it soft or watery (Types 6–7). Fluids, fibre, exercise, stress, illness, medicines and your menstrual cycle can all shift where you land.
See your GP if your stool type changes for several weeks without an obvious reason, or if you notice blood, black tar-like stool, unexplained weight loss or ongoing tummy pain. Our red-flag guide explains what each sign can mean.
Types 3 and 4 are considered ideal. Type 4 — like a sausage or snake, smooth and soft — is often called the gold standard.
Types 1 (separate hard lumps) and 2 (lumpy sausage) usually indicate constipation: stool has stayed in the bowel too long and lost water.
Types 6 (mushy, ragged pieces) and 7 (entirely liquid) indicate diarrhoea. Keep hydrated and see a GP if it lasts more than 7 days or you see blood.
It was developed at the Bristol Royal Infirmary in the UK in the 1990s and is now used by doctors worldwide to describe stool form.