Drinking coffee? By the time you’re finished reading this, you’ll probably have to poop.

Just me? Yes? 1/3 of you are lying!
Just me? Yes? Oh.

The Problem

Pooping and coffee. Coffee and pooping. If you’re part of the 30-ish % of people who get the urge to purge your bowels after your morning cup, coffee’s ability to make you go poo has not gone unnoticed by you, dear reader. But why does something so wonderful do something so unpleasant? Don’t worry, science is on it like flies on…poop.

The Study

  • A group of people were awkwardly asked if they felt like coffee normally made them feel like pooping. Scientists divided the group into “Nope, no pooping here” and “Yes! Coffee! Pooping! That’s me!”.
  • Brave, brave souls Scientists placed special instruments inside of peoples’ colons to measure movement (of where the poop is, y’all) and pressure. Yup. Because science!
  • The people with the probes were then given regular coffee, decaf coffee or hot water. The probes measured muscle movement and colon pressure to see which beverage caused the most action.

The Results

  • The people who said that coffee made them feel like pooping did, in fact, have more movement in their distal (lower) colons after drinking coffee (but not hot water) than people who said they didn’t notice the poo a’ flowin’ post java.
  • There was no (significant) difference between colon action in people who drank regular vs. decaf.*
  • Colon action started within 4 mins, which is way faster than it takes for the coffee to actually get to the colon (weird, right?!).

*There was a significant difference in the amount of awesomeness in those people though. Come on, decaf? Lame.

Picture originally from Hyperbole and a Half. Sentiment from me.
Picture originally from Hyperbole and a Half. Sentiment from me and all the other non-morning people out there.

The Takeaway

  • Yes, coffee does indeed make you poop (well, 30% of you).
  • You can get the same benefits from decaf (but really, decaf? I guess if you want to be miserable in other ways…).
Pretty much.
Pretty much.
  • Scientists aren’t really sure what it is in coffee that creates the poop action (technical term). Some ideas are that coffee might cause stomach acid to be made, or release something in the stomach called an exorphin.
  • Coffee = poop is most common in women (Boooo? Yay? hard to decide where I come down on that one…).

Need further stimulation? Check out the original study from the journal Gut.

To poop or not to poop, what does coffee do to you? Comment below!


Author: Emily

I started Rise and Sci because I love science, I love teaching people new things and I want to help build a greater public understanding of all things science. My goal is to take hard to understand concepts and make them accessible to everyone- all in a fun an interesting format!

12 thoughts on “Drinking coffee? By the time you’re finished reading this, you’ll probably have to poop.”

  1. Some of us don’t like the caffeine in coffee; I get all jittery and talk too much. No shame in decaf!

    I don’t drink enough to notice poop, but it makes my pee smell different. Anyone else? Will I regret putting that on the Internet? Probably.

    Liked by 1 person

    1. This reminds me of a magnet my Grammy used to have on her fridge- it said something like “Is the earth shaking or is it just me? Coffee!” I’ll tone it down on the decaf hate ;). I’ve never paid attention to pee smell, other than when I eat asparagus, promptly forget I ate asparagus, and immediately think I’m dying the next time I go to pee. Interesting observation, though!


  2. There’s simply too much privilege being part of the majority in most spaces in my life. I’ll wear the mantle of coffee-pooping stoically. As long as reading one’s phone on the John is stoic. šŸ’©šŸ˜„šŸ’©

    Liked by 1 person

  3. This is totally me (TMI?) and where I fall on the issue…very much a good thing….as long as I am in the comfort of my own home. Otherwise, looks like it’s a tea day!

    Liked by 1 person

  4. Very entertaining, Emily! However, I feel that my own demographic has been severely overlooked. Sometimes I get the coffee poops and sometimes I don’t. I guess it depends on whichever way the wind is blowing at the time. šŸ™‚


    1. According to the study linked at the end of the post here, yes! I was surprised, too! Speaking of surprise, did you know our fight or flight reaction makes us have to poop, also? Gotta lighten the load to be able to run away faster!


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