Human Feces - Bristol Stool Scale

Bristol Stool Scale

The Bristol stool scale is a medical aid designed to classify the form of human feces into seven categories. Sometimes referred to in the UK as the "Meyers Scale," it was developed by K.W.Heaton at the University of Bristol and was first published in the Scandinavian Journal of Gastroenterology in 1997. The form of the stool depends on the time it spends in the colon.

The seven types of stool are:

1. Separate hard lumps, like nuts (hard to pass)
2. Sausage-shaped but lumpy
3. Like a sausage but with cracks on the surface
4. Like a sausage or snake, smooth and soft
5. Soft blobs with clear-cut edges
6. Fluffy pieces with ragged edges, a mushy stool
7. Watery, no solid pieces. Entirely Liquid

Types 1 and 2 indicate constipation. Types 3 and 4 are optimal, especially the latter, as these are the easiest to pass. Types 5–7 are associated with increasing tendency to diarrhea or urgency.