The Bristol Stool Form Scale
The Bristol Stool Scale or Bristol Stool Chart is a medical aid designed to classify the form of human feces into seven groups. It was developed by Heaton and Lewis 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.
Type 1 has spent the longest time in the colon and type 7 has spent the least. Stools at the lumpy end of the scale are hard to pass and often require a lot of straining. Stools at the loose or liquid end of the spectrum can be too easy to pass - the need to pass them is urgent and accidents can happen. The ideal stools are types 3 and 4, especially type 4, as they are most likely to glide out without any fuss.
What type of stools are best?
*When it comes to defining the "ideal" stool, there is some debate. For another interpretation, please view Fiber Menace.