There's a Scale for Your Poop. Here's How to Read It.

Poop is one of the most important (and visible) biomarkers of your gut health. It’s also surprisingly complex—a watery mixture of bacteria (living and dead), cellular lining, fiber, fats, proteins, mucus, bile, and other compounds your body couldn’t digest.

Many of us sit on the toilet, casually scroll TikTok or Instagram, flush, and move on with our lives without ever examining what we are eliminating. We tend to take notice only when things go awry—when we haven’t gone to the bathroom in a few days, or when we haven’t left the bathroom in a few days.

Once again, decoding your stool isn’t that simple. Even subtle changes in the size, shape, texture, consistency, buoyancy, and frequency of your bowel movements can speak volumes about the state of your gastrointestinal tract, if you know what you’re looking for. Fortunately, there’s an app for that—well, sort of.

Developed by Dr. Stephen Lewis and Dr. Ken Heaton at the University of Bristol (England) in 1997, the Bristol Stool Chart is a universal classification system for human feces. Consider it a decoder for your toilet bowl—and an index of your gut health and function.

Poop Types 1 or 2
If you’re on this end of the spectrum, you’re likely constipated.

Poop Types 3 or 4
These are ideal poop types—expelled easily in a singular sausage or snake-like shape—they’re not too watery and not too dry.

Poop Type 5
If your poop looks a bit soft with ragged edges, it’s likely you need a bit more fiber in your diet to bulk up your waste.

Poop Types 6 or 7
On this end of the scale, you’re likely experiencing diarrhea.

Most of us will experience the entirety of the Bristol Stool Scale. One or two days of abnormal bowel movements is normal—common, even. It’s not until the irregularity becomes a pattern that intervention may be needed.

First things first, know that you’re not alone. 61% of Americans deal with digestive issues.¹ And it’s no wonder—just about everything we do on a daily basis contributes to the quality of our output—what we eat, what we drink, how stressed we are, how well we’re sleeping, how much we exercise, etc.

That said, there are a handful of choices that can have an outsized impact on the quality and frequency of your bowel movements—specifically, increasing your dietary fiber intake, and introducing beneficial bacteria, or probiotics. Let’s dive in.

Movement = Bowel Movement

Simply stated, regular exercise (or non-exercise physical activity) may support keeping you regular. 

In a 2006-2007 study conducted on high school-aged adolescents in Hong Kong to find whether or not constipation was associated with insufficient physical activity and excessive sedentary behaviors, results revealed that “constipation was identified in 15.6% of adolescents overall, 14.0% in those with sufficient exercise, and 19.6% in those without” — if the association is causal, constipation could be prevented by promotion of physical activity.²

Those individuals studied who remained sedentary had a higher occurrence of constipation.

Big Takeaway: In addition to endorphins, physical activity may provide other indirect health benefits.

Increase your fiber intake

You probably already know that fiber is good for you. But do you know why? Here’s a quick primer—fiber is a complex carbohydrate that cannot be digested by the human body. Commonly found in plants, fiber has a number of beneficial effects on the body, from influencing glycemic (blood sugar) response and maintaining healthy cholesterol levels to reducing the risk of colon cancer.

There are two basic types of fiber—soluble and insoluble. Soluble fiber absorbs water to form a gel-like substance in your digestive tract. It helps soften your stool for easier and better poops. Insoluble fiber is the ‘roughage’ found in stalks, skins, and seeds. It doesn’t dissolve in water, isn’t absorbed into the bloodstream, and helps bulk up your waste to keep you regular.

The National Institute of Medicine recommends a daily fiber intake of 25 grams for women and 38 grams for men. The average American gets only 16 grams a day. Fortunately, fiber is easy to get—fruits, vegetables, nuts, and whole grains are all naturally rich in it.

Introduce beneficial bacteria (probiotics)

Probiotics have been studied extensively to support gastrointestinal health and function. In fact, localized digestive benefits are often the most immediate and visceral experienced when starting a probiotic.

That’s because beneficial bacteria perform countless functions related to digestive health, including supporting the production of neurotransmitters that influence muscle contractions for motility and ease of expulsion (think: good, regular poops).

In fact, in a 300-person study,³ researchers also discovered that two specific strains (Lactobacillus plantarum SD-LP1-IT and Bifidobacterium breve SD-BR3-IT) support gastrointestinal functions such as bowel movement regularity, stool consistency, ease of expulsion, bowel movement comfort, and bloat ease.

In some cases, fiber and bacteria can even work together to deliver additional benefits. Some strains of gut bacteria can ferment fiber into short-chain fatty acids (SCFAs), important compounds that fuel the cells lining your colon, strengthen your protective intestinal mucus later, and influence the genes that control cell growth. SCFAs are also being studied for their role in motility.

The reality is, most of us will experience the entirety of the Bristol Stool Scale at some point(s) in our lives. One or two days of abnormal bowel movements is completely normal. But when it comes to ongoing digestive health, the key thing to remember is: Better inputs, better outputs.

1. Almario, C. V., Ballal, M. L., Chey, W. D., Nordstrom, C., Khanna, D., & Spiegel, B. M. R. (2018). Burden of Gastrointestinal Symptoms in the United States: Results of a Nationally Representative Survey of Over 71,000 Americans. American Journal of Gastroenterology: Volume 113 – Issue 11 – p 1701-1710. doi: 10.1038/s41395-018-0256-8
2. Huang, R., Ho, S. Y., Lo, W. S., & Lam, T. H. (2014). Physical activity and constipation in Hong Kong adolescents. PloS one, 9(2), e90193. https://doi.org/10.1371/journal.pone.0090193
3. Del Piano, M., Carmagnola, S., Anderloni, A., Andorno, S., Ballarè, M., Balzarini, M., Montino, F., Orsello, M., Pagliarulo, M., Sartori, M., Tari, R., Sforza, F., & Capurso, L. (2010). Journal of clinical gastroenterology, 44 Suppl 1, S30–S34. https://doi.org/10.1097/MCG.0b013e3181ee31c3