This for me was prime bucket list material, and having found a WG with this on her likes list, I have gone for it.
Agreed the attraction for me is all a part of the medical/ role play scenario so its all part of the scene.
This Gal had done her research,and knew all the ins and outs, and carried it out very professionally, in fact a couple of times.
As an experience, no great sensations, but a real big one (3 litres in my case) does take some evacuating, and its a great experience being in the hands of a sexy nurse taking control of your basic functions.
More phycological stimulation than physical, for me anyway, but I would go again, like a shot.