I hope you don't mind a female response here...

I can't do it all the time. I have to be in the mood for it. But when i'm in the mood i can open more and enjoy the pleasure of it. I don't like to have my ass fingered at all. I do enjoy a vibrator in there though, my ass has some nerve receptors that respond to the vibration. The stimulation from the inside also gets my gspot and clit from the backside.

It feels divine. No one enjoys anything up their ass if they arent prepared, ready and aroused for it. So accepting a docs finger is uncomfortable- especially with hemmorhoids!

Don't compare anything you receive in the doctors office as what you might feel with another patient, gentle person.