In a discussion I had with a man recently he pointed out that in the 1950s and much of the 1960s Processed foods were actually seen as a good thing, and the latest and greatest.
There was far less interest in working out and keeping in shape ESPECIALLY for women, and to a lesser extent men who had been though a lot physically in WWII.
I asked him if he thought the tight girdles that were standard "girl gear" back then were part of that also. His response: "That sure didn't help! How much it contributed is had to say objectively."
Sooo I think we can safely conclude that the conditions were certainly right for vastly more real constipation than exists today.
Those of you old enough to remember, What's your take, were enemas more common at least partly because real constipation was just more common?