I've only had two, both from the same male family med doctor. The first one was a complete surprise, I was not expecting it at all. I had just pulled up my pants, thinking we were done, after he finished the genital and hernia exams. So my head was already spinning. That's when he walked over to the table and told me to lean over it so he could check my prostate next. I think I was in shock during that exam, I don't remember registering much feeling (physically that is) from it. I remember that it did not hurt or feel good, just weird. Kind of a fullness, but not bad at all. I've read a lot of men feel pressure, or that they have to pee, or a tingling in the head of their penis. I didn't feel any of that. Over in less than 10 seconds or so. Mentally, my head was spinning with all kinds of thoughts and emotions. Plus, I was doing my best to try and mentally record all that I was feeling and experiencing so I could replay it in my mind later (my main medfet goal). My main thoughts and emotions were typical for me during an exam (any and all exams, this one just amplified)... Embarrassment, dread, anxiety, humiliation, exhilaration, vulnerable, controlled. You name it. To me, the worst part of the exam is after I'm bent over the table and the doctor is seated behind me inspecting my butt. Hasn't put his finger in yet, just spreading, looking, and touching. I feel so vulnerable, open, and on display. So judged.
My recent second exam was a completely different experience than my first. This was not a surprise, so at least the shock element was removed. There was far less visual inspection to begin with, that was good for me. But the physical sensation was way different than my first exam. I'd say in a good way, but I'm not entirely sure. The first gentle touch of the cold, slippery finger pausing on the butt hole is such a unique mixed feeling of trepidation and exhilaration. I could feel every bit of him slowly inserting his finger into me as he said, "Ok. Uh, this is just gonna, be a little on the uh, uncomfortable side....". Then suddenly, I could feel it. All the feelings I have read about, but didn't experience on my first exam. There was a slow building of pressure, almost felt hot, deep inside. Then the strange, tingling feeling in the head of my penis started. I'm not entirely sure if it was a good feeling or just a different, strange feeling. Either way, it was having an effect on me. When I stood up to pull my pants up, I was beginning to chub up a bit. Not full fledged, but probably noticable. I'm not sure if it was from the physical sensations, or the mental embarrassment/ excitment of the whole experience. But either way, it was definitely a unique and rememberable experience.