Amanda Norcross • May 19, 2021
Do you get the urge to run to the bathroom after you finish your coffee every morning? It's possible your coffee is making you poop, though caffeine isn't necessarily the culprit. Read on to find out why coffee makes you poop.
"Coffee contains chlorogenic acid, which stimulates acid production of a hormone called gastrin," explains Keith-Thomas Ayoob, EdD, RD, FAND. "Gastrin triggers lots of stomach acid and enzyme production to aid digestion. Gastrin can also lead to contractions of the colon and thus, defecation."
Another reason coffee makes you poop is something called a gastrocolic reflex. "When the stomach fills with food or liquids, it stretches. Gastrin can also have a hand in this, along with other hormones," Ayoob says. "Together, they trigger the colon to get active—kind of like a signal to the colon that more food is coming so it's time for contractions that will push out what's there to make room for what's coming."
Caffeine is a stimulant, which means it triggers activity in your brain, nervous system, and yes, your colon. "The stimulatory effect of the caffeine in coffee causes the intestines to react and become spasmodic, to a degree," explains Trista Best, registered dietician at Balance One Supplements. "This motion, again, causes the bowels to need to quickly empty themselves." This causes an increase in bowel movements and for some, diarrhea.
Coffee is complex, and in addition to caffeine and chlorogenic acid, there are other compounds that might contribute to the urge to poop.
Yes. Like regular coffee, decaf coffee contains cholorgenic acid and thus gives you the urge to poop.
The laxative effect doesn't happen for everyone. "Only about 3 in 10 people will have this response to coffee," explains Ayoob. "It's more likely with regular coffee than decaf, since caffeine adds its own stimulatory effect on the colon, but since both trigger gastrin production, you can still see effects with decaf coffee."
Ayoob notes the aforementioned effects of coffee seem to be more "vigorous" in the morning hours, waning a bit as the day wears on. "Modulated by hormones, intestinal motility is naturally slowed during sleep, decreasing peristaltic movement," explains Mary Ann Rollano, RN and author of Life Is Better With Tea. "Upon waking up, intestinal motility resumes and increases peristalsis. The increased intestinal motility combined with a dose of caffeine will cause the typical morning bowel movement most people experience."