Perhaps I can add to the discussion insofar as the UK and its (then) colonies and commonwealth countries are concerned.
Certainly up to and including WW2 enemas were commonplace, and I remember seeing in an article in the British Medical Encyclopaedia (found in the reference library at my school), that a Higginson syringe would be found in at least 50% of homes. Certainly from late Victorian times onwards, syringes for enema administration were to be found in profusion. After WW2, and up to the early seventies, the enema was still a common feature, although given the British sensitivities, this was never spoken about in polite company, any more than the entire topic of sexual activity. However, having grown up in the immediate post war period, (the so called golden age), I can confirm from personal; knowledge that, in my environment at least, an enema could be found in at least one home in two, if not more. I was something of an observer (you might say a gentle snooper), since at first I thought I was the only person in the world to ever get an enema. I was curious to know that I was not alone.
I did not have to look far, and in most bathrooms with a medicine cupboard, the apparatus could be found.
Around 60% were enema cans, and the balance the Higginson enema syringe. This was particularly true in the colonies, where there might not be immediate access to medical assistance, and households were often prepared to deal with simple medical procedures.
Enema equipment was to be found in most chemist shops, and frequently on display. Certainly, up to and including the early seventies, you could buy an enema syringe at any of the large pharmaceutical chains, such as Boots The Chemists. Perhaps not in every small branch, but certainly at the big outlets in larger cities. Boots, at that stage, still had their own house brand, which was known as the "Regaid" enema syringe.
Also, at this time, many rubber goods for personal use (i.e. condoms) were available at slightly shady outlets - sometimes known as rubber shops. There would be many types of enema syringe available, and on display. Perhaps this was indicative of the fact that there was a thriving klisomophile population. It was certainly not something that would have been discussed publicly at that stage. Us Brits of that and previous generations, were, and probably still are pretty uptight folk. It may well also be something of a class thing - given that British society was then far more class conscious than our more democratic transatlantic cousins. Anything to do with reproduction or bodily functions was strictly off limits in what would be regarded as polite in upper middle class society.
From the middle seventies onwards, enema equipment seemed to disappear from local pharmacies, but could still be found in the larger retail chemists, such as those in London, who stocked all manner of what were known as sick room requisites. However, I have never seen disposables on display or for sale - as one does everywhere in America. Based on the fact that disposables can virtually always be found within easy reach in the American drugstores and supermarkets I have seen, seems to indicate to me that enemas, at least in the land of the free and the home of the brave are as popular as ever!
Again, from personal observation, and certainly in the seventies, enema equipment was as common in countries such as France and Spain.
Another quirk, was the British tendency to bestow impressive names on the various models of enema. The Ingrams "Perfex" enema perhaps being the most frequently encountered in my time, but I have seen reference to doughty syringes with names such as the "Sterilendum", the "Victoria", the "Molusca", the Satinetta", the "Buckingham", the "Regaid" and the like - seems rather strange in todays world.
Interestingly, if you google 'Ingrams Enema", and then click on 'images' you will find somewhere in there a facsimile of an advert by Ingrams, for their products - and the claim that for the modern home, the enema was was an essential household item for the family. I don't know where the advertisement would have appeared, or what date it might be, but it seemed remarkably forthright on the subject.
Hope this casts some light on the topic. I could not claim that this as definitive, but is certainly based on personal observation.
Regards,
Delia