I remember Irie saying that Trixie was actually male, right? The pet store or somewhere sexed him wrong?
Rabbits generally do fine with a neuter, and before they leave give them a long lasting dose of pain meds, so I would say he would be fine. Males are usually quite good, and should be up and back to his normal self by tomorrow, or at least the next day. I wouldn't personally worry about pain medications at this point unless he seems to be in pain or in severe discomfort.
Bruno didn't get any pain medications to take home with, just the dose at the vets before he left, and managed very well.
*ETA - Oh yup, Trixie is male.. just went back and looked at her old post.