I do not know about the "Golden Age" but here is something about my own childhood.
In France, it used to be often the case (and still is but to a much lesser extent) that public restrooms, including those in schools, were of the squat type. I suppose that this is for sanitary and economical reason: one can clean squat toilets with less work than a sit-down type, there are fewer nooks and crannies, and there is no skin contact when using them.
At the same time, such toilets are awkward to use (unless perhaps you have one at home, which nobody has in France). Thus many children avoid them.
Also, some schools tended to have too few toilets and not enough break time.
This probably incited some children to avoid drinking (to avoid urges to pee) and to postpone pooping. Both may result in constipation.
I was myself constipated in elementary school (with squat toilets) but it stopped in teenage years (no squat toilets).
(The perception by parents of the importance of constipation in children differed, it seems. My parents were afraid of "impaction", that is, severe constipation that would earn a hospital trip to be settled, and thus took action. I don't think today's parents are so afraid.)