Some people swear that turkey makes them sleepy or gluten makes them ill and the science community is not going to spend any time at all thinking about those outside trivia quizzes.

And some people have a cup of coffee and then go number two and they think the coffee is causal. Is it, or is it just that, like hunger pangs in people who don't eat for a few hours, some parts of biology are learned?

https://www.popsugar.com/fitness/why-does-coffee-make-you-poop-46626165