What the fuck?

Edit: Sorry to be brusque. You're suggesting that it's conscionable to disallow a bathroom break that would inconvenience customers or cause a fellow employee to be unable to progress? That category of work culture should be unheard of in the USA, but it's leaking in, and if we don't viciously reject it, we might as well start the country over.

If bathroom breaks are frequently causing some kind of unacceptable complication, then the problem isn't the bathroom break, it's the design of the position.