But how limited were the positives to having "centers of enema use?"
"(at home) Enemas were given for just about any ailment in those days."
And for how many of these ailments did they really help? Some, possibly, and they likely didn't cause harm (physically) provided people knew how to do them, but enemas can be upsetting, especially for children. Again, not completely negative here, just playing devil's advocate. Definitely enemas are better than running indiscriminately for antibiotics if you must "feel you're doing something," but a medical rationale requires some level of proof.
"The other "center" was the hospital. When you checked in for surgery the day or night before you got an enema -- hopefully after visiting hours. Oftentimes before you were discharged to go home you were given an enema. These were not squeeze bottles, they were bags or buckets of warm soapy water."
Again (and especially here), what was the true benefit? You're embarrassing patients and causing them discomfort to what end. I imagine that there may be some benefit to going into surgery with empty bowels (actually more than imagine, as an enema was recommended to me prior to a surgery because of my history of constipation) and making sure you go home with bowels empty (for a multi-day stay), given that opioids are known to cause constipation and anaesthetics seem to mess up my bowels as well, but couldn't that be handled just as easily at home? The prior rationales of "pooping on the operating table" and potential damage to the intestine causing infection have been (as far as I know) disproven or are no longer relevant.
A big part of the concern here is that most of these situations involve actual power imbalances, such as parent/child, doctor/patient, nurse/patient (except, ideally, husband/wife, which should be on an equal plane except when you want to play with consensual power imbalance). When there is an actual power imbalance having a valid justification is much more important.