Bristol Stool Chart
Seven types, one scale. The Bristol Stool Chart sorts stool by shape and consistency, and what it really measures is how long things spent in your colon — hard and lumpy means slow, watery means fast. Types 3 and 4 are the target.
Pick the type that looks closest to yours to jump straight to what it means and what to do about it.
Last updated 13 August 2026 · Based on the Bristol scale as published by Lewis & Heaton (1997)
Type 1 — Separate hard lumps
About 100 hours in the colon
Stool sat in the colon long enough for most of its water to be reabsorbed, leaving small, hard pellets that pass separately and often painfully. Type 1 is the clearest sign of slow transit and is usually uncomfortable to pass.
Common causes
- Not enough fibre, or a sudden drop in it
- Dehydration — the colon pulls water back out of stool
- Ignoring or delaying the urge to go
- Low physical activity, bed rest, or long travel
- Opioid painkillers, iron supplements, some antacids and antidepressants
What to do
- Increase water before increasing fibre — fibre without fluid makes constipation worse
- Add soluble fibre gradually (oats, psyllium, chia) over a week or two, not overnight
- Move daily; even a 20-minute walk speeds colonic transit
- Go when you feel the urge rather than holding it
- Use a footstool to raise your knees above your hips, which straightens the rectal angle
Type 2 — Lumpy sausage
Slower than ideal
A single sausage-shaped mass made of compacted lumps. The pieces have joined together but the stool is still dry and hard, and often takes straining to pass. Type 2 is the most commonly reported constipated form and frequently causes haemorrhoids or anal fissures over time.
Common causes
- Chronically low fibre intake
- Not drinking enough through the day
- Irregular meal or bathroom timing
- Low activity levels
- Common in IBS-C (constipation-predominant IBS)
What to do
- Work toward 25–30 g of fibre a day from food, increasing slowly
- Drink consistently through the day rather than a lot at once
- Keep a regular routine — the colon responds to predictable meal and sleep times
- Never strain; straining is what turns type 2 into haemorrhoids
- Track whether it correlates with travel, stress or a medication change
Type 3 — Cracked sausage
Normal transit
Sausage-shaped with cracks along the surface. Type 3 is a normal, healthy stool — slightly firmer than ideal but easy to pass and requiring no straining. Together with type 4 it is what you want to see most of the time.
Common causes
- A balanced diet with adequate fibre
- Reasonable hydration
- Regular bowel habits
What to do
- Nothing needs fixing — keep doing what you are doing
- If it drifts toward type 2, add fluid before adding fibre
- Note what your normal looks like so you can spot a real change later
Type 4 — Smooth snake
Ideal transit
Smooth, soft and sausage- or snake-like, passing easily and in one piece. Type 4 is the clinical gold standard: it means water absorption, fibre intake and transit time are all in balance. This is the target.
Common causes
- Adequate fibre from a varied diet
- Good hydration
- A settled, regular routine
What to do
- This is the goal — no change needed
- Consistency matters more than any single result; watch the pattern over weeks
Type 5 — Soft blobs
Faster than ideal
Soft blobs with clear-cut edges that pass easily. Type 5 is not diarrhoea, but it does mean stool is moving through faster than ideal and is often a sign of too little fibre to give it form. Occasional type 5 is unremarkable; a steady run of it is worth addressing.
Common causes
- Not enough fibre, particularly soluble fibre
- A recent diet change or an unusually large meal
- Mild food intolerance
- Caffeine or alcohol earlier in the day
- Stress — the gut-brain axis speeds transit
What to do
- Add soluble fibre (oats, bananas, psyllium) to give stool more form
- Look at what you ate in the previous 24–48 hours, not just today
- Watch for a pattern with dairy, caffeine or specific foods
- If it persists more than a week or two, start logging it properly
Type 6 — Mushy, ragged edges
Fast transit
Fluffy pieces with ragged, torn edges — a mushy stool. Type 6 means the colon did not have time to absorb enough water, and it often comes with urgency. A single episode usually reflects something you ate; a run of them points to an ongoing trigger, an infection, or a digestive condition.
Common causes
- Food intolerance — lactose and gluten are the usual suspects
- A gut infection or food poisoning
- Antibiotics disrupting the gut microbiome
- Stress or anxiety
- IBS-D, inflammatory bowel disease, or coeliac disease
- Excess caffeine, alcohol or artificial sweeteners
What to do
- Stay hydrated — add electrolytes if it happens repeatedly
- Keep a food and symptom log; the trigger is usually 12–48 hours earlier
- Ease off caffeine, alcohol and sugar alcohols for a week and see what changes
- If it follows a course of antibiotics, mention it to your doctor
- See a doctor if it lasts more than a few days
Type 7 — Entirely liquid
About 10 hours in the colon
Watery, with no solid pieces at all. Type 7 is true diarrhoea: stool passed through so fast that almost no water was absorbed. The immediate risk is dehydration, especially in children and older adults. Isolated episodes are common; persistent type 7 always needs looking into.
Common causes
- Viral or bacterial gastroenteritis
- Food poisoning
- Traveller's diarrhoea
- Medication side effects, antibiotics in particular
- Flare of inflammatory bowel disease
- Severe food intolerance
What to do
- Prioritise rehydration — water plus an oral rehydration solution, not just water
- Eat plain, easy foods once you can keep them down
- Avoid dairy, caffeine and fatty foods until it settles
- Wash hands thoroughly; infectious causes spread easily
- Seek medical care if it lasts beyond 2 days, or immediately for the red flags below
What counts as normal
The range of normal is wider than most people assume. An occasional type 2 or type 5 is not a problem — your own baseline, and changes to it, are what matter.
- Frequency
- Anywhere from three times a day to three times a week. There is no daily quota — consistency in your own pattern matters more than hitting a number.
- Ease of passing
- You should not need to strain hard or spend more than a few minutes on the toilet. Straining is the part that causes damage over time, not the stool itself.
- Colour
- Medium to dark brown is typical. Black, red, white or persistently pale stool is worth acting on; a one-off green after a spinach-heavy meal is not.
- Change over time
- An occasional off day is meaningless. A shift that lasts more than a week or two, with no obvious dietary explanation, is the signal worth paying attention to.
When to see a doctor
Whatever your Bristol type, these symptoms need medical attention rather than a diet change:
- Blood in your stool, or black tarry stool
- Diarrhoea lasting more than 2 days in an adult, or 24 hours in a child
- Signs of dehydration — dizziness, very dark urine, passing little urine
- Severe or persistent abdominal pain
- Unexplained weight loss
- A lasting change in bowel habits, especially over the age of 50
- Fever alongside digestive symptoms
- Pale, clay-coloured stool, or stool that is persistently greasy and floats
One reading is a snapshot
A single type tells you very little. The pattern over weeks — and what you ate, drank or worried about before it — is where the answer actually is. Flushy logs it in seconds and finds the correlation for you.
Frequently asked questions
What is the Bristol Stool Chart?
The Bristol Stool Chart is a medical scale that classifies human stool into seven types by shape and consistency. It was developed at the Bristol Royal Infirmary and published by Lewis and Heaton in 1997 as a practical way to estimate how long stool spent in the colon. It is used in clinics worldwide to describe bowel habits without ambiguity.
Which Bristol stool type is healthiest?
Type 4 — a smooth, soft, sausage-shaped stool — is considered ideal. Type 3 is also healthy. Both pass easily without straining and indicate that transit time, fibre and hydration are in balance.
Is Bristol type 5 diarrhoea?
No. Type 5 is soft blobs with clear-cut edges that pass easily, which is not diarrhoea. It usually indicates a lack of fibre and faster-than-ideal transit. Diarrhoea begins at type 6 (mushy with ragged edges) and type 7 (entirely liquid).
What does Bristol type 6 mean?
Type 6 is mushy stool with ragged edges and counts as mild diarrhoea. It means the colon did not absorb enough water because stool moved through too quickly. Common causes include food intolerance, gut infection, antibiotics, stress and IBS.
How often should you poop?
Anywhere from three times a day to three times a week is considered normal. Consistency matters more than frequency: a stable pattern of type 3 or 4 is healthier than a daily type 1 or type 6. What matters most is a change from your own normal.
When should I see a doctor about my stool?
See a doctor if you notice blood or black tarry stool, diarrhoea lasting more than two days, unexplained weight loss, severe abdominal pain, or a lasting change in bowel habits — particularly if you are over 50. Pale or clay-coloured stool also needs prompt assessment.
Can I change my Bristol stool type?
Usually yes. Fibre intake, hydration, physical activity, stress and medication all shift stool consistency, often within days. Tracking which of those you changed alongside the resulting type is the fastest way to find what moves your own numbers.
Keep reading
Sources & disclaimer
- Lewis SJ, Heaton KW. “Stool form scale as a useful guide to intestinal transit time.” Scandinavian Journal of Gastroenterology, 1997 — the paper that introduced the scale.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — guidance on constipation and diarrhoea.
- NHS — bowel symptom guidance and when to seek care.
This page is general health information, not medical advice. It cannot diagnose a condition. If you are worried about a symptom — especially bleeding, persistent pain or a lasting change in bowel habits — speak to a doctor.