My wife felt the same way- she said it was indeed kind of a turn on- in getting ready for and then receiving her first rectal from a real doctor...What added to it, I believe, was that the doctor was our new neighbor, and who’s medical visits have certainly become a turn on for me.
Over the years, I would sometimes give her rectals when we played doctor...but she had no knowledge how real or fantasy it was, not actually having gotten one from a real doctor at an exam.
Now, being a male, I am clearly used to regular rectals from any doctor...it just turns out this cool guy moves in next door and becomes not only our neighbor but also our doctor.
He was really thorough when he saw me and when, during my wife’s exam, he was the same. During the last part of the pelvic she heard him say “now you are going to feel a little pressure back here from my finger, and when you do, bear down like you are going to the bathroom,” she was startled/aroused/embarrassed/and ready to play when she got home.
We had drinks with our neighbors the next night and all I could “visually picture” was this good looking man, my age with his finger in my wife’s rectum, while he chatted with her about our collective kids and she became aroused.
Good times, and the Dude Abides!