Sometimes, though, coffee can have an, um, interesting effect on certain parts of our digestive system. No, you’re not imagining it: Drinking coffee does sometimes makes you need to poop—and often, quite urgently.
Why does coffee make you poop?
According to Shiv Desai, MD, a gastroenterologist with Austin Gastroenterology in Texas, coffee has multiple effects on your gastrointestinal tract, both good and bad. Indeed, some evidence suggests it can make heartburn symptoms worse, and it may worsen symptoms in people who have gallstones. But the results of a study published in JAMA Oncology in September 2020 suggest that coffee might actually help slow the progression of advanced or metastatic colorectal cancer. But why does it make you need to poop? Right now, we’re not entirely sure of the precise reason, but scientists propose a few possibilities. Some studies suggest that caffeine in coffee may be a factor. Caffeine is a stimulant, and it can stimulate your intestines to start moving. But Dr. Desai points out some conflicting evidence.“But if caffeine was the only criteria, then most people would have similar effects when drinking a soda with caffeine,” says Dr. Desai. “But we know this isn’t the case.” It might be some other factors at work, too.For example, coffee increases the level of a hormone called cholecystokinin that stimulates the release of bile into the intestine from the gallbladder and stimulates gut motility. In other words, it gets things moving.
How much coffee are we talking about?
To some degree, it depends on how “full” your colon is, says Dr. Christine Lee, MD, a gastroenterologist with the Cleveland Clinic. If you haven’t had a good poop in a while, and you down a cup of coffee, “it can stimulate your colon to promote a gastrocolic reflex or a bowel movement,” says Dr. Lee. Or, as she adds, “You pull the trigger, and you’re going to have a response very quickly and very promptly.” While that might happen pretty quickly for some people, it might take an hour or so–or longer–for the effect to kick in for other people. “That can also vary from person to person,” says Dr. Lee. Wondering if you should start drinking more coffee if you need a little boost to get things moving? You probably shouldn’t boost your coffee consumption for this exact reason, especially if you’re already drinking a fair amount. And different people have different responses to coffee. “I generally do not recommend excessive coffee intake–more than four cups a day–as this can lead to downstream side effects such as fast heart rate and sleep-related disturbances,” says Dr. Desai.
What about decaf?
Turns out, decaf coffee has a very similar effect to the full-octane version–that is, drinking decaffeinated coffee can also make you poop. Dr. Desai points to a 2019 presentation at Digestive Disease Week, an event put on by the World Endoscopy Organization, about a study in rats that looked at a complex interaction of the gut biome and motor complexes that seemed to regulate colonic activity and movement of the bowels. “The most important point was decaffeinated coffee or caffeinated coffee did not matter,” he says.
What will happen if I add milk and creamer to my coffee?
It will taste delicious. (Okay, so that’s a matter of opinion.) Adding a dairy product like creamer or milk to your coffee will boost the calorie content, which may or may not matter to you.But it won’t undermine the other effects of the coffee. And if you’re lactose intolerant, it might trigger a bowel movement anyway, says Dr. Lee.
Should some people avoid drinking coffee for this reason?
Are there people who may want to avoid drinking coffee because it makes them need to poop? That depends.Dr. Lee says that she has many patients with inflammatory bowel disease (IBD) who undergo treatment to suppress their autoimmune systems so their bowel function is normal. When they’re in remission, there’s no reason to avoid coffee. But people with irritable bowel syndrome (IBS) might want to be more cautious. The caffeine may trigger a bout of diarrhea, and diarrhea is already a problem with many cases of IBS. Some research suggests that you might want to limit your daily caffeine consumption to 400 mg or less, if you’re not already doing so. If you don’t have any underlying health conditions that are exacerbated or triggered by coffee, but you don’t want to make a mad dash for the toilet after a cup of joe, make an effort to empty your bowels well when you do go.“The best way is to keep your colon as empty as possible,” says Dr. Lee. Next up, what causes constipation? Here are 8 reasons why you can’t poop, according to doctors.
Sources
Dr. Shiv Desai, MD. Austin GastroenterologyDr. Christine Lee, MD. Cleveland ClinicScandinavian Journal of Gastroenterol Supplement: “Coffee and gastrointestinal function: facts and fiction. A review"World Journal of Gastroenterology: “Diet in irritable bowel syndrome: What to recommend, not what to forbid to patients” JAMA Oncology: “Association of Coffee Intake With Survival in Patients With Advanced or Metastatic Colorectal Cancer.” Front Endocrinol: “Cholecystokinin-From Local Gut Hormone to Ubiquitous Messenger.”
