This is EXACTLY where I started my fetish.
It was done in the morning, with my parents instructed to keep me up most of the night to get me tired. Early in the morning before sunrise (so it was "nighttime"), I was taken to the children's hospital in my pajamas and placed into a room with another child also there for surgery. For years I thought I had spent that first night in the hospital, years later I understood what went on.
They left us in the dark and told us to go to sleep, but we chatted and became friends. The hospital bedspread was identical to mine at home but a different color, and much conversation ensued about our bedrooms.
The nurse finally came and yelled at us; we were supposed to "go to sleep until morning" or we would be in big trouble. We were not allowed to talk anymore
I did not want to be in big trouble.
I laid down on my belly with my head turned to the right like I always did and tried to go to sleep. I often had a hard time falling asleep, and this was no different. The other child did fall asleep, as far as I know.
A while later, the nurse came in. I pretended to be sound asleep (I had done this before at home...my not-sleeping was a frequent issue). She did not turn on the lights, but the shaft of light from the door came across my bed. My head was facing away from the door, but I could see the light through my eyelids.
She pulled down my pajama bottoms and a heard a crinkling noise. Then she wiped the right side of my bottom with something. Then, for some reason she pinched my bottom. I laid very still, doing my "dead weight" imitation until she stopped pinching me--I wondered if she was checking to see if I was awake.
Then, she ever-so-gently spread my buttocks apart and put something cold on my anus. For a moment, I was afraid she was going to take my temperature and it would hurt, but she slid something soft into my bottom and it did not hurt at all. It felt funny, but I was not scared.
I suddenly felt very warm in my penis, and I realized I was getting an erection. I had experienced them before, and I knew I would get in trouble with one. But nobody saw it as I was face down on the bed. I was worried, because if somebody saw it they would get mad, and I knew nurses liked to pull your pants down a lot.
She took the thing out of my bottom, pulled up my pajama bottoms and left, quietly closing the door.
The warmth traveled from my pelvis throughout my body, and everything went funny.
The next clear memory was me in the room. It was daylight. My roommate was gone; never saw him again. My throat was sore, and I did not remember them using the special root-beer scented oxygen mask we had talked about. It was just over. My grandparents visited and brought me a toy motorcycle that had a buffalo skull on the handlebars (I still don't know why, I never liked motorcycles). My other grandmother brought me a stuffed dog.
I was finally allowed to go home late in the evening when I was urinating to their satisfaction. I remember it came out green (methylene blue?) I had a lot of popsicles, not ice cream like my mother had promised, and was not feeling well at all when we left. But I was very ready to go home.
In retrospect, I realized that the crinkling was a paper disposable syringe package like they used in the early 1970s. The alcohol wipe, the injection so skillful that I thought it was just a pinch...those were all things that would be in my nighttime fantasies for the rest of my childhood. I used to lie in bed, pull down my pajama bottoms and poke my bottom with a 300-ohm antenna wire, dreaming of that funny feeling in the hospital.
But it was the rectal administration that still thrills me now. I'm fairly certain it was probably a rectal administration of some sort of narcotic analgesic, perhaps a tincture, probably from a red rubber catheter. Though it could have been a suppository that she held in place until it melted.
I do know that I got warm all over (like an alcohol flush) and the erection was a physiologic reaction. The warmth started in my penis and testicles, then spread outwards, more-slowly at first and then instantly I was warm and comfortable and very sleepy.
You can see how memorable it was. I don't have more than 15 more distinct memories that whole year that I can call up, but that experience, I can bring up in perfect detail 37 years later. In particular when the nurse came in...I replayed that memory over and over for years. It is the longest intact memory of my childhood before first grade.
Clearly I had been "caught" with erections previously and been punished or scolded; I don't remember those instances, I just knew that having one was A Bad Thing.
In many ways, that was my first sexual experience. I felt that drug right down through the glans of my penis and it was a wonderful feeling I did not experience again until the first time I masturbated to ejaculation (which was actually probably even better) around age 13-14. Once I discovered that skill, I would sometimes masturbate to that memory. My mother had saved my hospital arm bracelet for a scrap book and I would sneak it out, lay it across my wrist and and masturbate to great satisfaction.
After the operation, I got very sick and nearly died from an allergic reaction. But that did not start until the night after we left the hospital, and the memories from the green urine onward are lost. I think my father had gotten worried before we even left the hospital and argued with the staff over it. I do remember there was conflict, and I had to keep urinating until something happened and we could leave, or they would give me an IV, or something. I remember thinking it was like a threat of punishment.