Bristol Stool Scale

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Last year, the University of Bristol celebrated their 100-year anniversary. Prestigious institution of higher learning. Produced nine Nobel laureates and the Bristol Stool Scale, a medical tool used to classify the fecal form. Seven different classifications: 

Type 1: Looks like rabbit droppings. Separate hard lumps, like nuts; hard to pass.
Type 2: Looks like a bunch of grapes. Sausage-shaped, but lumpy.
Type 3: Looks like corn on the cob.
Type 4: Like a sausage or snake, smooth and soft.
Type 5: Looks like chicken nuggets. I don’t think I’ll be able to look at chicken nuggets quite the same way ever again.
Type 6: Looks like porridge; and…
Type 7: Looks like gravy. You got to love them Brits.

The best #2 is a #4; a smooth and soft snake. Unfortunately, only a minority of adults enjoy normal bowel function, and only about half pass normal stools. Wow. And younger women, due to hormonal fluctuations throughout their cycle, are particularly disadvantaged.

But this is for people eating a standard Western diet. Wouldn’t it be neat if some researchers compared bowel function measurements between individuals eating different diets? It would, and they did.

Bowel function was assessed: omnivores, versus vegetarians, versus vegans. Each subject was provided with a “stool collection kit,” a stack-a-boxes each used to accommodate one stool only, reducing the risk of specimens becoming squashed. They weren’t messing around.

So, meat-eaters versus plant-eaters, put to the test. First question: where did the meat-eaters fall? Does the average bowel movement of meat-eaters look like rabbit droppings, bunches of grapes, corn on the cob, a smooth and soft sausage, chicken nuggets, oatmeal, or gravy?

Meat-eaters, on average, poop out corn cob stools. What about vegetarians? 1, 2, 3, 4, 5, 6, or 7? #4, right where we want to be. And finally, what about vegans, on average? #4 as well.

But, vegans actually ended up beating vegetarians, because none of the vegans had the hard rabbit-turd stools, whereas a few of the vegetarians, like a bunch of the meat-eaters, struggled to pass type 1s. And, the smooth vegan snakes were softer—exactly 18% softer. How could they tell? Using a stool penetrometer, of course.

An editorial in the Canadian Medical Association Journal celebrated the finding this year, calling on doctors to tell all their patients to eat a plant-based diet, as vegetarian diets can only help push patients into the comfortable middle range of the much-beloved Bristol Stool Scale.

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• G.J. Davies, M. Crowder, B. Reid, & J.W. Dickerson. Bowel function measurements of individuals with different eating patterns. Gut, 27(2):164-169, 1986.
• E.S. Weiss. Stop the beef eaters, save the world. CMAJ, 182(6):636, 2010.

• bowel movements
• colon health
• constipation
• diarrhea
• Plant-Based Diets
• vegans
• vegetarians