The Explosive Diarrhea Myth That's Actually Backed By Science

There are many misconceptions about diarrhea. One probably even involves your favorite morning beverage. Although it's a myth that coffee automatically causes problems with explosive diarrhea, there are several nuances to consider. In fact, it's scientifically proven that coffee can exacerbate diarrhea problems, and that certain underlying conditions might increase your risk of having this type of reaction to your regular cup of joe.

To understand why coffee can cause diarrhea in the first place, it's important to remember that caffeine is a stimulant. Caffeine has many effects on your body, and while some people might rely on them for a quick way to wake up and get some energy, the stimulating effects of caffeine go beyond your central nervous system. Drinking a cup of coffee also increases gut motility, creating a laxative effect. This can lead to increased digestion and bowel movements. It's these effects that explain why regular coffee drinkers tend to experience bowel movement regularity. If you find yourself running for the nearest bathroom after a cup of coffee though, chances are that the beverage could be making an existing medical condition worse.

Some people with irritable bowel syndrome (IBS) may already experience stronger intestinal contractions on a regular basis that increase the risk of diarrhea. Throwing caffeine in the mix could make things worse by increasing diarrhea events, says Johns Hopkins Medicine. In other cases, the culprit might not be the coffee at all. If you take milk in your coffee, either IBS or lactose intolerance could cause an adverse gastrointestinal (GI) event. Also, while not considered an established direct cause of IBS, research published in Frontiers in Nutrition in 2021 suggested that coffee consumption was associated with an increased risk of IBS in adults.

Coffee gets the most attention for exacerbating GI issues, but it isn't the only culprit behind worsening diarrhea. The same can be true of any caffeinated beverages or foods, including  teas, sodas, energy drinks, and chocolate. Even decaffeinated coffee can be problematic for some people, since it still contains about 1 milligram of caffeine per 8 ounces, which can stimulate the GI tract. Quantity also matters. As the International Foundation for Gastrointestinal Disorders notes, drinking two to three caffeinated beverages per day may lead to diarrhea in some people.

While coffee isn't a direct cause of explosive diarrhea, you might consider talking with a health care professional if you do experience loose stools after drinking coffee. It's also recommended to talk with a doctor if you have more than six loose stools per day, diarrhea that continues for longer than two days despite home treatments, or any case of diarrhea accompanied by a high fever.