The Bristol Stool Form Scale
Developed in 1997 at the University of Bristol, this 7-category diagnostic chart is used by clinicians worldwide to evaluate bowel transit time and gastrointestinal health.
Separate hard lumps
Separate hard lumps, like nuts (hard to pass). Indicates significant dehydration and slow intestinal transit.
- Increase soluble and insoluble fiber
- Drink at least 2.5L of water daily
- Incorporate gentle walking or abdominal massage
Sausage-shaped, but lumpy
Sausage-shaped but lumpy. Sign of mild constipation and prolonged colon transit time.
- Add chia seeds or ground flaxseed
- Maintain regular hydration intervals
- Evaluate magnesium intake
Like a sausage with surface cracks
Like a sausage but with cracks on its surface. Normal, healthy stool with adequate fiber content.
- Maintain current balanced dietary pattern
- Continue consistent daily hydration
Smooth and soft sausage or snake
Like a sausage or snake, smooth and soft. The gold standard of digestive wellness and balanced microbiome transit.
- Excellent microbiome stability
- Keep consistent sleep and dietary habits
Soft blobs with clear-cut edges
Soft blobs with clear-cut edges (passed easily). Slightly fast transit, typical after high-fiber meals or mild stress.
- Ensure balanced insoluble vs soluble fiber ratio
- Observe tolerance to trigger spices or dairy
Fluffy pieces with ragged edges
Fluffy pieces with ragged edges, a mushy stool. Indicates rapid colonic transit or mild inflammation.
- Focus on electrolyte replenishment
- Temporarily favor bland foods (BRAT diet)
- Monitor food sensitivities
Watery, no solid pieces
Watery, no solid pieces; entirely liquid. Severe hypermotility or acute digestive upset.
- Immediate rehydration with oral electrolytes
- Avoid caffeine, dairy, and hyperosmolar drinks
- Seek medical advice if sustained >48h or accompanied by fever