Well, if anyone had reason to fell vulnerable the first time, I think I had a pretty good reason. I was confined to a head-to-knees body cast, and in traction.
The MD overseeing me had visited that morning, and had noticed I hadn't had a movement since the cast went on five days before, so he ordered an enema. I had never had one before, so I asked what was involved. He replied, as a joke, "We'll put some water up your rectum and wash it out with high pressure."
(Now before anyone jumps all over that man, I should say that if he hadn't caught the spinal curvature I was developing, I probably wouldn't be walking today. One wing of the hospital where this happened is named for him, and when he pased on some seventeen years later, I noted his obituary, and told the fraternity brothers I was living with at the time that we'd all lost a friend.)
But at any rate, an hour or so later a young male intern came in with a Fleet, and I went through the same procedure three days later the night before my surgery.
Three days after that, the MD's decided yet another enema was in order, but this time around, the tried-and-true method was used. I got a quart or so of warmed soapsuds via the traditional "irrigating can", and the two older female nurses who performed the duty (and appeared to be enjoying it) told me, "This is the kind you'll get when you go home."
At the time, I wasn't too happy over that prospect, but the warm water and the ladies' willingness to explain things did put an end to most of the anxiety, and I got much better results. The nurses left the can where i could see it for a while, and I could remember wondering why such a violation of my body could leave me feeling so much better.
As it turned out, I needed no enemas once I returned home, but when the hormones began stirring a few years later, taking an enema seemed as arousing an act as bathing, so I began experimenting.
So the only way I can draw a paralell in this instance would be to liken my indroduction to the benefits (and pleasures) of the enema as something similar to the ritual of intimidation, followed by bonding, which occurs in young men when introuced to "locker room cameraderie" via Phys Ed, contact sports, the military, etc.