Why Coffee Makes You Poop—and How to Delay the Urge

Can you really start your morning off right without a cup of coffee? For some, coffee doesn't just put a pep in their step, it also wakes up their bowels.

coffeeWAYHOME studio/shutterstockCoffee is known to give people a boost in energy, while also boosting their bowel movements. Although there hasn’t been much research on the subject, a study from Gut, a journal of gastroenterology, shows that 30 percent of people have to run to the bathroom after drinking coffee. And with the average American drinking almost three cups of coffee per day, that means there’s a lot of people hopping on the toilet post-java.

“Coffee stimulates the contractions of the stomach and intestinal tract, and it stimulates bile excretion, which itself is a propellant of food particles because the intestines know that when there is bile there is food,” Dmitri Alden, MD, a colon health specialist at Lenox Hill Hospital, told BuzzFeed.

Coffee is able to affect digestion through way of the central nervous system. Once stimulated, the central nervous system communicates with the stomach through branches of the autonomic nervous system, the part of the nervous system that controls the heart and digestive tract. All this movement forces the colon to work harder and push whatever’s in there out. While the physiological mechanism is understood, it’s still unclear what part of coffee causes this laxative effect.

It has been said that the amount of caffeine in coffee could be one reason for an increased urge to poop. “Hot beverages in general may also tend to have this effect, so a hot caffeinated beverage might be a double whammy,” says Monica Reinagel, MS, LDN, from NutritionOverEasy.com.

There is also the possibility that coffee’s acidity plays a part. The Washington Post reports that a compound found in coffee called chlorogenic acid triggers higher acid levels in the stomach and higher production of gastric acid. That bump in overall acidity could force the stomach to push out its contents faster than usual. With an incredible amount of chemicals—over 1,000 aroma compounds to be exact—it’s hard to tell which one is responsible for the boost.

How to prevent the need to go

Some research suggests regularly consuming coffee diminishes the effect. A study published by the Journal of Human Nutrition and Dietetics found that a tolerance for the diuretic properties of coffee develops when habitually consumed. Reinagel couldn’t speak on the validity of the research, but she explains that people who regularly consume caffeine do develop a tolerance to its effects. “Coffee does not actually have any diuretic effect in regular coffee drinkers, for them, drinking coffee is equivalent to drinking plain water in terms of hydration,” says Reinagel. (Did you know drinking coffee can also help you live longer? Here’s how.)

And while the laxative effects of coffee are experienced with or without cream, dairy, and non-dairy milk, if you’re sensitive to dairy, adding them into your morning “cup of joe” definitely isn’t helping your stomach. So try drinking it black or with non-dairy creamer.

So, why does coffee make you poop? Unfortunately, there’s really no definitive answer to this coffee-pooping conundrum; the only solution is to know your body and brew yourself that cup of coffee at your own risk.

Have more coffee questions? Here are answers to some of the most important coffee questions.

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