But is this merely a coincidence, or does hot coffee truly have the potential to instigate more frequent BMs compared to iced options? In search of a definitive answer, we spoke to Will Bulsiewicz, MD, a board-certified gastroenterologist and the author of Fiber Fueled.
An intro to coffee and increased bowel movements
To start, Dr. Bulsiewicz reminds us that coffee in general is proven to get things *moving along* in your digestive tract. “The reason this happens is that both regular and decaffeinated coffee increase the activity of the colon, leading to more pressure waves,” he explains. And it all happens rapidly at that, as the GI doc notes that heightened activity occurs in as little as four minutes from coffee consumption. “We suspect it is due to hormones that get released in response to the coffee, given how quickly the motility can ramp up,” he continues.
From there, you may be wondering if any coffee order will do the trick. “The available evidence would suggest that caffeinated coffee is the most stimulating to the colon, followed by decaffeinated coffee,” Dr. Bulsiewicz says. Beyond that, once you throw in creamers, sweeteners, and the like, your BMs may vary based on your own body’s response to the different additives—say, if you have trouble digesting lactose or need something to counter the acidity of your brew.
Each of these points considered, Dr. Bulsiewicz notes that while drinking coffee results in a bowel movement more often than not, digestive responses (and other bodily effects) do vary from one person to the next. “We are all different and have an individualized response to coffee. There are some who don’t have bowel movements with coffee, while there are others who may actually have diarrhea,” says Dr. Bulsiewicz. “But for most of us, coffee helps to stimulate a nice, satisfactory morning visit to the loo.”
Does hot coffee make you poop more than iced coffee?
On this million-dollar question, Dr. Bulsiewicz says that the jury is still out and that studies are necessary to answer it with certainty one way or another—even if you do, in fact, notice that your BMs are more frequent or sizable after sipping on hot coffee. (That said, practitioners of modalities including Ayurvedic and Traditional Chinese Medicine suggest that warm and room temperature beverages are more optimal for digestion than cold ones, as the latter are said to slow down the digestive system.)
“Unfortunately, there hasn’t been clear research to define the effect of beverage temperature on bowel movements,” Dr. Bulsiewicz says. However, he cites a 2014 study on rats published in the World Journal of Gastroenterology, in which colon motility was slower when the rats were given cold water compared to room temperature water.
“Clearly, we need human studies to understand this better,” Dr. Bulsiewicz continues. But until those are underway, he suggests putting on your own researcher hat to see if your own digestive system leans one way or another when it comes to consuming hot vs. iced coffee. “Try drinking your coffee iced for a week and then warm in a different week and keep track of how often you have a bowel movement, the Bristol stool type [of which there are seven], and whether or not it was a satisfactory BM,” Dr. Bulsiewicz advises. At the end of your DIY experiment, he invites you to tally the results and share them with him on social media.