Why Coffee Causes Bowel Movements, Explained by a G.I. Doctor and Science

For numerous coffee enthusiasts, the bathroom break following a morning cup is as certain as the dawn. But whyis coffee one of the drinks that cause immediate bowel movement, even if it’s decaffeinated?

Although caffeine can stimulate your digestive system, it is the coffee bean that actually causes this sensation, according toJosephine Ni, MD, a gastroenterologist from the University of Texas Southwestern and a specialist in inflammatory bowel diseases.

DoesDoes caffeine cause you to need to use the bathroom?

Put simply, yes. CaffeineIt doesn’t only awaken your brain—it also enhances digestive system activity. Specifically, caffeine activates your colon, causing contractions that assist in moving waste through, according to Dr. Ni. At the same time, caffeine “reduces the sensory threshold for the urge to have a bowel movement,” she notes, meaning your body becomes more responsive to signals from your gut indicating it’s time to go.

But intriguingly, a 2022 study published inNutrientsfound, rats that were given decaf coffee showed comparable bowel movement patterns to those that received caffeinated coffee. This indicated that additional components in coffee may also be involved.

Here’s what causes coffee to lead to a bowel movement

Dr. Li mentions that coffee increases gastrin levels. This hormone causes what is known as the “gastrocolic reflex”—a message from your brain to your digestive system when your stomach is full, which creates the need to have a bowel movement. This reflex happens whenever your body is prepared for a bowel movement, but coffee enhances its impact.

She mentions that coffee also increases another hormone known as cholecystokinin (CCK). This signaling molecule instructs your pancreas to secrete digestive enzymes and causes your gallbladder to contract and release bile—both essential processes in the sequence of events that result in abowel movement. 

The acidity of coffee may also be a factor, according toKris Sollid, RD, the senior director of research and consumer insights at the International Food and Information Council.When coffee increases our gastrin hormone levels, the body generates more stomach acid to initiate digestive activities.Coffee also includes chlorogenic acid, a natural antioxidant found in plants.

Sollid states that both of these acids reduce the stomach’s pH level and accelerate the passage of food from the stomach to the intestines, causing the stomach to expel its contents more quickly than it would naturally.

Can you stop the desire to have a bowel movement?

For many, having a bowel movement after a morning latte is a regular occurrence, but it’s more than just a habit. “The stimulating effect of coffee on digestion has been studied compared to a placebo,” says Dr. Ni, and the urge to go after drinking coffee is due to how coffee helps move your digestive system, not simply because of routine.

“Some individuals may become tolerant to the laxative impact of coffee with time,” she adds. However, this is probably because of a higher tolerance tocoffee’s caffeine, not its other components. This is why switching to decaf may not necessarily lessen coffee’s effect on stimulating the bowels. For instance, “both caffeinated and decaffeinated coffee have been found to trigger the release of gastrin and CCK,” says Dr. Ni.

Is this a beneficial stimulus-response situation?

In most instances, coffee’s impact on your digestive system is a typical reaction. Indeed, consuming coffee is associated withbetter gut healthand a variety of additional advantages. As per 2025 research published in theEuropean Heart Journal, consuming coffee in moderation is linked to a reduced risk of type 2 diabetes, cardiovascular issues, and overall mortality—particularly if consumed during the morning hours.

Nevertheless, Dr. Ni mentions that certain individuals are more reactive to coffee and its impacts, particularly those with pre-existing gastrointestinal (GI) conditions like irritable bowel syndrome (IBS) andinflammatory bowel disease(IBD). “Coffee may act as a trigger for their symptoms,” however, she notes that additional research is required to comprehend this variation in sensitivity among people.

There are also elements that could cause your brew to be slightlytoostimulating. “Coffee syrups may include sugar substitutes, such as”sugar alcohols, which are osmotic laxatives,” Dr. Ni explains. “Additionally, adding dairy—something that over one-third of Americans are intolerant to—can lead to gastrointestinal symptoms and increase the need to have a bowel movement.”

If you are sensitive to coffee’s laxative effects, consider drinking itblackTo determine if you’re responding to something you’re adding to your mug. Alternatively, Dr. Ni advises opting for tea or a carbonated beverage with caffeine as an energy boost. However, if you’re having unpleasant bowel movements after drinking coffee, Sollid suggests talking to your physician about gastrointestinal symptoms to explore any potential underlying health conditions, like a digestive disorder.

Get daily wellness updates by subscribing toThe Healthy by Reader’s Digest newsletter and follow The Healthy on Facebook and Instagram. Keep reading:

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