In the second movie, while he's drunk at a party he hosted, he grabbed a mic and told the crowd that the most asked question to him was "How do you go to the bathroom?"

To which he replied that he'll show them, and promptly poops his armoured pants.

You are now realizing Tony Stark most likely has a built-in diaper.

you dont?

He's got a filtration system built into it.

and his piss into excellence

>Implying you wouldn't shit yourself at the prospect of flying into the mouth of a giant armoured space eel.

It even beeps when he goes to the bathroom
...
Boop Boop Boop Boodooboop

the suit wipes for him

at the very least, he's gonna be fighting loki with a dirty arsehole

I assume he has some sort of bag to shit in anyway.