About 10 years ago, I was in the hospital for an infection. It had settled in my right wrist and right foot and was a painful SOB. So, along with the antibiotics, I was the recipient of some pretty stout opiate pain meds. After a few days, I became painfully aware that I had not had a BM in a while. I wasn't up to walking to the bathroom, so they brought in a bedside commode and I transferred to that. Some time spent straining convinced me that regardless of my anal hobby, disregarding all my stretching, and ignoring all the times I'd been fisted, what was inside was very solid, very large and not coming out. My hole simply wouldn't stretch that big. One of the nurses said that she could reach inside and break it up if it was OK with me. At that point, it would have been OK with me if she'd said she was going to drill and blast. As my mind is racing "Fisted and insurance is paying?" I stifled my "Oh hell yeah!" and meekly said, "Do whatever you gotta do."
She had me bend over the bed, resting on my forearms and began breaking up and removing the blockage. Even in my dilaudid addled mental state and despite the pain of the infection, I enjoyed it. She did each insertion very fast. Just like doctors do DREs. I think it's so the patient won't think, "This pervert's enjoying having a hand up my ass." I thought about saying "If you'll slow down, I'd enjoy that", but I figured that'd get me on a "naughty" list somewhere. About a dozen insertions, I guess, and she said, "That should do it." It did and I was able to finish the BM the boring way.
So, yeah, you can get fisted at the hospital, but considering how bad you have to be hurting before they do it, it's better to just find a play partner and get fisted at home.