And not just because of the coffee.

Last month, Starbucks announced it was testing out an unexpected new line of drinks that had everyone talking. The line, named Starbucks Oleato, features several different coffee drinks that combine Starbucks Arabica coffee and Partanna cold-pressed extra virgin olive oil. After generating a lot of early buzz and controversy, the line of drinks has started rolling out in Starbucks Reserve Roastery locations nationwide.

Early reviews on the Oleato drinks have been mixed, with some commenters on Instagram raving, "It’s a delicious combination," and, "I tried Oleato at the Reserve Roastery in Chicago and it was immaculate." Other reactions have skewed negative, saying the drinks taste like an, "oil spill," with some people claiming it's, "the most vile coffee drink I have ever had."

But there is one reaction Starbucks perhaps did not anticipate—the drinks causing some unexpected side effects in customers. It's widely known that coffee can make some people need to use the bathroom, but apparently the Oleato drinks are taking this effect to the extreme.

Starbucks’ Oleato Drinks Are Causing Stomach Issues in Some Customers

Early commenters on Starbucks promotional teasers warned of this effect, writing, "Olive oil and espresso, sounds like a great idea for a laxative." But the concept really took off when one Reddit thread in which a Starbucks employee detailed their team's experience with the Oleato drinks went viral.

"I’m wondering how many people are going to have happen to them what a few happened to our team,” wrote Reddit user u/MoodyStarGirl. “Half the team tried it yesterday and a few ended up... Needing to use the restroom, if ya know what I mean..."

From there, the comments started rolling in. One user pointed out, "Caffeine is a stimulant for your bowels and oil a relaxant. So yeah wonderful idea by Starbucks." "I tried one and immediately had a shooting stomach pain so this is going to go over so well," commented another.

The sentiment has been confirmed across various social media platforms. We'll spare you the worst comments, but they range from the hilarious—"that oleato drink from starbs makin my stomach speak"—to the alarming—"so far my stomach is gurgling and my throat is burning."

Why Are the Starbucks Oleato Drinks Making People Poop?

As we know, coffee has a laxative effect for a variety of reasons. But, as some commenters have pointed out, oils are thought to be a relaxant for the gut. A 2015 study even found that olive oil in particular was helpful in combatting constipation, with the theory being that it helps lubricate the digestive system and softens stool. However, it's important to note that consuming too much oil can cause diarrhea.

This is not the first time in the last few weeks that the internet has inadvertently fast tracked their digestion. And while it can yield some pretty hilarious comments, it shouldn't be taken lightly. Those with bowel issues or sensitive digestive systems may want to sit this trend out, especially considering those Starbucks bathrooms are never open, anyways.