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Why Does Coffee Make You Poop With Regularity?

Have you ever had the experience of drinking a cup of coffee and then having to head for the bathroom pronto? Can coffee make you poop or is it a myth? Find out!
Why Does Coffee Make You Poop With Regularity?
Fresh baked bran and flax muffin and coffee

OK, we admit that this is not one of the great medical mysteries of all time. It is intriguing, though. You might think that researchers have far more important things to do than try to figure out can coffee make you poop, and if so, why? It turns out that they have been struggling over this coffee conundrum for years. There may now be a plausible explanation. It was presented a prestigious meeting of gastroenterologists.

Coffee Makes Him Go to the Bathroom:

Q. I have found that my body reacts in a very predictable manner to my morning cup of coffee. Usually within 5 to 10 minutes I have to go to the bathroom. Is it the caffeine or something else in coffee that stimulates the bowels?

Does the Caffeine in Coffee Make You Poop?

A. You are not the first person to notice this effect. We used to think the caffeine was responsible, but scientists have shown that both regular and decaf coffee stimulate colon activity (Gut, April 1, 1990).  Caffeinated coffee does seem to have a stronger effect, however (European Journal of Gastroenterology & Hepatology, Feb. 1998). 

How Many People Are “Moved” by Coffee?

The small study in the journal Gut cited above reported that 29 percent of the volunteers in their study claimed “that coffee induced a desire to defecate.” That could be right, but we would need to see much larger numbers to find that stat convincing. There were only 99 volunteers willing to participate in that research. The actual number could be substantially higher for all we know.

Does the Acid in Coffee Make You Poop?

Some scientists have attributed the laxative effect of coffee (regular or decaf) to its acid content. Chlorogenic acid can stimulate acid production in the stomach. The theory goes that this effect in turn triggers intestinal movements. So far, though, the data are not convincing.

Will the Magnesium in Coffee Make You Poop?

Some people suggest that coffee is high in the mineral magnesium. Everyone knows that magnesium has a laxative action. Just think Milk of Magnesia (magnesium hydroxide). A 2 oz cup of espresso has almost 50 mg of magnesium. But a regular cup of coffee has only about 7 mg of magnesium. That is not enough to get things moving.

What Really Makes Coffee Send You to the Bathroom?

Scientists have tested coffee in rats and found that both decaf and high-test increase the contraction power of intestinal muscle contractions. There are purported to be over 1000 different chemicals in coffee; hence the complex flavors and unique aroma. The researchers at the University of Texas, Galveston, did not identify which specific chemicals in coffee stimulate muscle movements within the digestive tract.

Coffee and the Microbiome:

The coffee treatments also changed the composition of the rats’ gut microbes, though no one is quite certain what that means for digestive health. One possible application of the coffee discovery is in the hospital, of all places.

When patients undergo abdominal surgery, they frequently develop something called post-operative constipation. When surgeons handle your intestines, the tissues tend to revolt by not resuming normal contractions for awhile. There are also the anesthetics, muscle relaxers, pain meds and the immobility of recovery. If coffee helps get the intestinal tract moving again, perhaps someday doctors will prescribe a cup of coffee in the days following abdominal surgery.

The investigators reported their research at a conference, Digestive Disease Week (DDW) 2019.

Share your own experience with coffee and trips to the bathroom in the comment section.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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