Which pain meds have the least side effects?

If my husband has surgery behind his scrotum to create a new exit point for urine, according to the neurologist, the post-op pain medicines may put him into a permanent "loopy" state. What pain medicines could he take safely without that side effect. The versed that was given for cataract surgery left him somewhat diminished for a while. We've tried the dilation of the penis for the past ten years with frequent urinary tract infections. A few months ago his urethra was perforated during dilation, landing him in the ER for a four-day hospital stay. Officials would not let me leave his room; a family member had to be with him at all times. He was not combative or otherwise acting demented; he had staph and strep infections!