Bristol Stool Chart
The Bristol stool chart sorts stool into seven types, from hard lumps to liquid. Choose a type above to see what it usually indicates.
Bristol stool chart (Bristol Stool Form Scale)
| Type | What it looks like | Passing | What it usually indicates |
|---|---|---|---|
| Type 1 | Separate hard lumps, like nuts | Hard to pass | Severe constipation |
| Type 2 | Sausage-shaped but lumpy | Often needs straining | Mild constipation |
| Type 3 | Like a sausage but with cracks on the surface | Easy to pass | Normal |
| Type 4 | Like a sausage or snake, smooth and soft | Easy to pass | Normal (ideal) |
| Type 5 | Soft blobs with clear-cut edges | Passed easily | Lacking fiber |
| Type 6 | Fluffy pieces with ragged edges, a mushy stool | Urgent | Mild diarrhea |
| Type 7 | Watery, no solid pieces — entirely liquid | Urgent | Severe diarrhea |
What is the Bristol stool chart?
The Bristol Stool Form Scale is a medical aid that classifies stool into seven types by shape and consistency. It was developed at the Bristol Royal Infirmary in England and published by Lewis and Heaton in 1997. Because the shape of stool reflects how long it spent in the bowel, the scale is used by doctors and researchers as a simple, shared way to describe bowel habits and gut transit time.
How to read the chart
Types 1 and 2 are hard and slow-moving — a sign of constipation. Types 3 and 4 are the normal range; type 4 is often described as ideal. Type 5 is soft and can suggest low fiber intake. Types 6 and 7 are loose or liquid and indicate diarrhea. One unusual day is common and usually reflects food, fluids, stress or travel; what matters more is a pattern over time.
Everyday factors that affect stool type
- Fiber: fruit, vegetables, whole grains, beans and lentils add bulk and soften stool.
- Fluids: too little water makes stool harder.
- Activity: regular movement helps the bowel work.
- Medicines and supplements such as iron, some painkillers and antibiotics can change stool consistency.
- Illness, stress and travel can cause short-term changes.
When to see a doctor
Contact a healthcare professional if you notice blood in your stool, black or tarry stools, a change in your usual bowel habit that lasts more than a few weeks, unexplained weight loss, severe or persistent abdominal pain, or diarrhea with signs of dehydration. Seek urgent care for heavy bleeding or severe pain. Children, older adults and people with long-term conditions should get advice sooner.
This chart is for general information only and is not a diagnosis or medical advice.
Notes
Types 1–2 indicate constipation, types 3–4 are normal, type 5 suggests low fiber, and types 6–7 indicate diarrhea. Based on the Bristol Stool Form Scale (Lewis & Heaton, 1997).
Frequently asked questions
What is a healthy stool type?
Types 3 and 4 on the Bristol chart.
What does type 1 stool mean?
Hard, separate lumps — usually constipation.
What does type 7 stool mean?
Watery stool with no solid pieces — diarrhea; watch for dehydration.
Who created the Bristol stool chart?
Lewis and Heaton at the Bristol Royal Infirmary, published in 1997.