[ineedasername]

That's not a strong argument for strict bathroom rules. That's an argument for guidelines that don't require explicit permission: let kids go any time they want, and they silently signal it by holding up 2 fingers as they get up & go.

And how much valuable time is lost here, weighed against the extreme distraction a student has if they can't go? Besides, once the student has raised their hand and been called on, the flow is already disrupted. Answering "yes" or "no" is irrelevant at that point.

Do you have a proposal that both meets biological needs and doesn't run the minor risk of disruption? Disruptions occur constantly anyway every time a student asks a questions when they don't understand, even when most others do.

I simply fail to see how "stop the flow of the lesson" is either very relevant to unpreventable biological needs, or an unsolvable problem in its own right.