Coffee is a popular morning beverage that not only provides a boost of energy but also numerous long-lasting health benefits when consumed in moderation. However, some coffee drinkers may experience the sensation of needing to go to the bathroom after drinking their morning cup of Joe, which begs the question, "why does coffee make you poop?"
If you've ever felt the urge to run to the bathroom after drinking coffee, you're not alone. In fact, a study of 92 participants found that 29% of them reported needing to use the restroom within just 30 minutes of finishing their cup of coffee.
To understand why coffee has this effect on our digestive system, we turned to Adil Maqbool, MD, a researcher affiliated with Toho University in Japan, and Onyx Adegbola, MD, Ph.D., a physician-scientist and lifestyle medicine physician. They explained that there are two main drivers behind coffee's effect on our bowel movements. One is related to how coffee interacts with the muscles in our colon, and the other is related to its impact on our production of gastric acid.
Why Does Coffee Make You Poop? Understanding the Effects of Coffee on Bowel Movements
The colon's movements and contractions are responsible for bowel movements, as they physically push the stool down and signal the body to defecate. Coffee is known to give the sensation of needing to use the bathroom, and this is because of the way it interacts with the colon's processes.
"Drinking coffee can stimulate the muscles in your colon, triggering bowel movements due to the caffeine, a natural stimulant compound," says Maqbool. In other words, coffee loosens things up to ease bowel movements.
Interestingly, decaf coffee, which still contains a small amount of caffeine, can also stimulate the colon. A study published in the European Journal of Gastroenterology and Hepatology found that caffeinated and decaffeinated coffee, as well as food, were more effective in causing colon contractions than water. While decaf coffee did lead to some colon movement, caffeinated coffee was still 23% more effective.
Coffee Can Stimulate the Release of Stomach Acid
Coffee has been known to stimulate bowel movements and speed up digestion, which can make you feel like you need to use the bathroom. The interaction between coffee and stomach acid plays a role in this process. According to Dr. Onyx Adegbola, coffee stimulates the production of gastric acid in the stomach and intestines, resulting in increased acidity that can speed up digestion and lead to the urge to poop. However, some people may experience stomach discomfort or cramping due to this interaction.
The level of acids found in different types of coffee can affect the amount of gastric acid production in the body. A study published in Molecular Nutrition Food Research found that a dark roasted coffee with lower levels of common coffee acids caused less gastric acid production than a different market blend.
If you experience acid reflux or frequent bathroom trips after drinking coffee, the Cleveland Clinic recommends trying low-acid options such as dark roasts, espresso, cold brew, or mushroom blends.