The Bristol stool chart, explained
General information, not health advice. Talk to your doctor or dietitian about your own symptoms.
Seven types, one scale. Here it is as simple diagrams, no photos.
Last updated 2026-10-31 ยท By Torstein Skulbru
The short version
The Bristol scale sorts poop into seven types by shape and firmness. Types 1 and 2 are on the firm, slow side. Types 3 and 4 are the middle. Types 5 to 7 are on the loose, fast side. The useful question is rarely "which type is perfect" and more often "what is normal for me, and has it changed?"
The seven types
Drawn as simple diagrams, not photos. The number always comes with the shape.
- 1
Type 1: Pebbles
Separate hard lumps, hard to pass
Firm
- 2
Type 2: Lumpy log
Sausage-shaped but lumpy
Firm
- 3
Type 3: Cracked log
Sausage with cracks on the surface
Just right
- 4
Type 4: Smooth snake
Smooth, soft, snake-like
Just right
- 5
Type 5: Soft blobs
Soft pieces with clear edges, easy to pass
Loose
- 6
Type 6: Mushy
Fluffy, ragged pieces, mushy
Loose
- 7
Type 7: Watery
Liquid, no solid pieces
Loose
What the scale is good for
The original study measured how long food took to travel through the gut in 66 volunteers. Stool form on the seven-point scale tracked that transit time better than how often people went or how much they passed. So the scale is a simple way to describe whether things are moving slowly, normally or quickly, and to notice change.
- Types 1 and 2 sit on the slow side. The NHS lists poo that is dry, hard or lumpy, or straining and pain when you go, among the signs of constipation.
- Types 3 and 4 are the middle of the scale.
- Types 6 and 7 sit on the fast side. The NHS says diarrhoea usually stops within 5 to 7 days, and to get urgent advice if it lasts more than 7 days.
Your normal matters more
People differ. The NHS advice on changes is about what is usual for you: changes in your poo, or needing to go more or less often than is usual for you, are worth getting checked, as is blood in your poo. A record over a few weeks makes it easy to see whether something has really changed.
Sources
- Stool form scale as a useful guide to intestinal transit time. Scandinavian Journal of Gastroenterology, 1997 (PubMed 9299672). The study behind the Bristol scale: in 66 volunteers, stool form on a 7-point scale tracked whole-gut transit time better than stool frequency or output.
- NHS: Constipation. Signs of constipation: fewer than 3 poos in a week, or poo that is unusually large or small and dry, hard or lumpy, or straining or pain when you go.
- NHS: Symptoms of bowel cancer. Used only for this advice: see a GP about changes in your poo that are not usual for you, or blood in your poo.
- NHS: Diarrhoea and vomiting. Diarrhoea usually stops within 5 to 7 days; urgent advice (111 in the UK) if it lasts more than 7 days.
Gutrude is a tracker, not health advice. Log the type in three taps and keep your own record.
