That's a great question - our gut is a super interesting system, and microgravity does affect it in some ways, though obviously it still works up there.

One thing that's important to note is that your intestines are long, and honestly kind of all over the place. We're talking around 7 meters (20+ ft), going down, sideways, and sometimes up. Between that and the fact that we digest laying down a lot of the time, one realises that gravity pushing that food down isn't really the main driving force. What does most of that job is layers of smooth muscle, that contracts and pushes things along without you even being conscious of it. So the fact that things float up there is not a huge deal.

But lack of gravity does tend to do things to fluids, however. With gravity, they typically settle pretty well, with gases coming back up and separating from the liquids pretty cleanly. Since liquids also become floaty blobs in space, that stops being the case. This means that our usual ways of expelling gases - burping and farting - may stop just expelling gases. Notably, burps often come up with what feel like acid reflux, and, well, one shouldn't trust a fart in space (Google Apollo 10 floating turd for an interesting tidbit).

Another thing of note is that for many astronauts, arrival in space can be accompanied by space sickness, usually nausea, vomiting and a generally upset tummy. This is a digestive issue too, but one mainly caused by the sensory adjustment to space.

TF2 heavy sounds

Mf is as funny as YouTube comments on a woman's video

Is it? One is a massively growing industry, the other is an established one. What else should people be expecting?