Bulimics actually do like throwing up, especially when it's been used as a coping mechanism and a way to feel in control for years, it's essentially like getting high for them. It's easy to assume puking sucks for them because for most people, throwing up DOES suck, it's something you only do when you're sick, and even then, people's natural instinct is to fight it. But bulimics are way past the ingrained fear of puking. They don't fight the gag reflex to not puke, and they don't feel pain from doing (not at first, anyways... later down the road, sure). It feels good for them, especially as a source of control. Don't take my word for it, go read bulimics testimonies or go check out some ED forums/ED reddit and read all about it; the way they talk about it, it sounds like a junkie shooting up herion.
That doesn't mean Tay always feels good doing it, especially after a long time, the damage adds up. And logically, I'm sure she knows this is not only hurting her, but it's hurting her parents too. That said, bulimics and ana-chans are legit addicted to their disordered habits because for them it is the ultimate source of control. A place like Fish Tank is probably one of the worst places for a recovered bulimic to go, not only because the environment encourages gross behavior (and bulimics don't mind gross stuff) but also because the enviroment is chaotic and they have very little feeling of control. I knew when she first threw up that she was going to relaspe.
Tay has taken every chance she could to puke, and she hardly eats, she does what all ED chicks do and stays drinking coffee and smoking cigs to stave off hunger. Another thing is, you can see how much chipper she acts after every time she pukes. This bish is feeling great after every purge.
Maybe someone with a more encyclopedic knowledge of bathroom happenings has evidence otherwise
Bulimics will purge in the shower if the toilet isn't an option. Some prefer it because then it means less clean up since they're already naked and can just wash the filth off.*
Tay is purging openly whenever she has an excuse to do so and there a non-zero chance she's purging in the shower when she doesn't have an excuse to do it in front of the cameras.
*Of course it does depend on what food they ate, you can't purge something chunky in the shower that won't go down the drain.