"Somehow, I lost the argument, because pissing yourself is a real possibility in this kind of situation and probably also because I was both wrong and high out of my mind."

Counterpoint: Adult diapers. Can any medical professional tell me why it wouldn't be cheaper and easier to put a diaper on to account for the POSSIBILITY of pissing one's self, rather than sticking a (w)hole tube up there?

Most importantly here, you can't access the femoral artery in the groin if a diaper is on. Other reasons include: it's important to keep track of how much urine the patient is making so the anesthesiologist can adjust the fluid rate. Also, there is no good way to change the diaper, and you don't want a wet diaper to sit there and cause skin breakdown.