The Bristol Stool Chart Explained: Types 1 to 7
By the GutBox team · · 6 min read
Nobody loves talking about poo, but it's one of the clearest signals your gut gives you. The Bristol Stool Chart (also called the Bristol Stool Form Scale) is a simple way to describe it without any awkwardness. It was developed at the Bristol Royal Infirmary in 1997 and is now used by doctors, nurses and dietitians around the world.
It sorts stools into seven types based on their shape and consistency. Broadly, the lower numbers point towards constipation and the higher numbers towards diarrhoea.
The 7 types
| Type | What it looks like | What it usually suggests |
|---|---|---|
| 1 | Separate hard lumps, like nuts. Hard to pass. | Constipation |
| 2 | Sausage-shaped but lumpy | Constipation |
| 3 | Like a sausage, with cracks on the surface | Ideal |
| 4 | Like a sausage or snake, smooth and soft | Ideal |
| 5 | Soft blobs with clear-cut edges. Passed easily. | Towards the loose side |
| 6 | Fluffy, mushy pieces with ragged edges | Diarrhoea |
| 7 | Watery, with no solid pieces | Diarrhoea |
What's considered ideal?
Bladder & Bowel UK describes types 3 and 4 as ideal. They're soft enough to pass without straining, but formed enough to suggest food is moving through your gut at a comfortable pace.
Don't worry about the odd type 2 or type 5. Everyone has variation from day to day depending on what they've eaten and drunk, how active they've been and how stressed they are. What matters is your usual pattern and any lasting change to it.
Types 1 and 2: on the hard side
Hard, lumpy stools usually mean poo has spent longer in the bowel, where more water has been absorbed. Common causes of constipation include not eating enough fibre, not drinking enough fluids, not moving much, ignoring the urge to go, changes to your routine, some medicines and stress.
The NHS suggests that eating more fibre, drinking plenty of fluids and being more active can help. Our guide to how much fibre you need covers practical ways to eat more.
Types 6 and 7: on the loose side
Loose or watery stools mean things are moving through quickly. A short bout of diarrhoea is common and often caused by a stomach bug, something you ate, alcohol or stress. It usually settles on its own within a few days. Keep drinking fluids to avoid getting dehydrated.
Bladder & Bowel UK advises getting medical advice if you haven't recovered after two weeks.
Why tracking your stool type is useful
A single bowel movement tells you very little. A few weeks of them can tell you a lot, especially next to what you've eaten. You might notice your stools get harder on low-fibre days, or looser after a particular food or drink.
Using the chart keeps your notes consistent, which makes patterns much easier to see. It's also exactly the language a GP or dietitian will use, so it makes appointments quicker and clearer.
In GutBox, a Gut Check lets you tap the stool type that looks closest, add any symptoms, and see it on the same timeline as your meals. If you're starting a diary from scratch, our guide on keeping a food and symptom diary explains what else to note down.
What about colour?
The Bristol Stool Chart only covers shape and consistency, not colour. Most poo is a shade of brown, and colour can change with what you eat. However, the NHS advises contacting NHS 111 or asking for an urgent GP appointment if your poo is black or dark red, or you have bloody diarrhoea.
Sources
This article is for general information only and isn't a substitute for advice from a doctor, dietitian or other qualified healthcare professional.