The sad fact is that medicine, even today, cannot cure many things. Half a century ago, even fewer cures existed.
For example, colds and 'flu cannot be cured. The best modern medicine can do is treat some of the symptoms and hopefully make the patient feel better.
Some vintage cold medicines, like Bromo Quinine, also had a laxative included, with the belief a good poo would help getting over a cold. Maybe, maybe not.
Then there is the placebo effect... sugar pills with no active ingredients can make a person feel better. And there is the perception that the worse a medicine tastes, the better it must be for you. Yes, old wives' tales, but often effective.
I see childhood enemas in this vein. Not those given by misguided parents as punishments, but enemas given during illness. Just doing SOMETHING can often help, even if the something is ineffectual. (Jefferson Airplane... White Rabbit... 'the pills that mother gave you don't do anything at all).
At least a mighty enema will do something, causing a stronger perception of effect than most any pills.