I've had all four of my laser lithotripsies done under a general, and actually the worst part of the whole experience was having stents in my ureters for a week post-op (they do this to keep them open after the 'insult' of surgical intervention). Still, it was better than having the stones in there, and they give you good pain medication if you need it.
Many people don't have any trouble at all; I guess my ureters are on the twitchy side---they don't want those stents in there, and they do their best to reject them!
Sorry about your stone problem..........it's no fun, I know.