As a play doctor, there's a number of things I fantasize about doing that I doubt I could or would ever actually do, to a play patient. I've got a bit of a sadistic streak in my fantasy world, but the problem is that deep down (shhhh, don't tell anyone!) I'm a fairly kind, empathetic guy. Plus, I know my limits and could never do anything that I fear would risk causing damage or leading to an infection. Also, when I say I'd like to make a patient suffer, it's always in a realistic sense that "I'm doing this for her own good"...
A few off the top of my head:
...catheterizing her and controlling her bladder, filling it, releasing it, entirely on my own determination. Her desperate need to pee vs. offering relief is entirely in my hands...
...injecting her in some very sensitive, very tender, very nerve-ending-rich places with a chilled, unbuffered local anesthetic that burns so good as it enters...
...dilating the cervix of a patient, leading to what would be likely awful, internal cramping that wouldn't be at all enjoyable, except for a masochist...
Truthfully, I can imagine getting the training, or finding simulated ways to do some of these (e.g. using sterile water and making subdermal or intradermal injections that burn but run a very low risk of infection), but I can't imagine finding a patient even remotely interested in this kind of play!
-TYD