I can honestly say that it's still a mystery to me how exactly I developed a fascination with medical fetishes. Even in early childhood, when I was no more than 5 or 6 y.o., just as I was beginning to discover the first traces of sexuality in my life, I quite accidentally began to realize that the only thing that aroused and attracted me was a woman's bottom. Not breasts, not a vagina (although, of course, at that time, I didn't yet know what the female reproductive system was or what female genitalia looked like). Only the bottom! And at that very moment, I began to realize that what aroused and attracted me most were medical procedures related to the butt. Enemas, suppositories, RT, rectal exams, etc. I finally realized this by the age of 7 or 8 y.o. It's important to note that I myself never underwent these procedures as a conscious child, only in the very first years of my life, of which I have only fragmentary and very vague memories.
And even in my teenage years, when I had access to the internet, I started watching porn and masturbating - I wasn't interested in the "mainstream" interests of boys my age. I had no desire to watch videos of men and women simply having sex, even the most bizarre practices. I only wanted to watch medical procedures involving women's (okay, sometimes men's too) bottoms and nothing more. Of course, spanking also aroused a certain (and not small) interest, but if you really think about it, even that can be considered an offshoot of medical fetish, so I never made a distinction between the two. I honestly can't even understand how or why this interest developed in me. I simply embraced it. And I've never regretted it one bit.