The Bristol Stool Scale is a medical classification that divides stool into seven categories. Since the shape of stool is related to the time it spends in the colon, it can be used to determine how long it takes for food to pass through the colon.
It was first published in 1997 in the Scandinavian Journal of Gastroenterology by Heaton and Lewis at the University of Bristol, UK.
Taxonomy: * Type I: one hard ball (difficult to pass) * Type II: sausage-like, but with a bumpy surface * Type III: sausage-like, but with a cracked surface * Type IV: sausage-like or snake-like, with a smooth surface * Type V: soft lumps with smooth broken edges (easy to pass) * Type VII: watery, no solid lumps (completely liquid) * Type VI: rough-edged fluffy lumps, paste-like stool Types I and II indicate The third and fourth types are the ideal stool shape, especially the fourth type is the easiest shape to pass; the fifth to seventh types represent possible diarrhea.