The pain meRAB notoriously cause constipation. I take a Colace capsule with each pain pill I take.
As others have said, add fiber, fruit, prune juice, etc. Whatever works for you. After my surgery, I took the Colace and also ate a few prunes everyday. They have cherry essence and orange essence prunes now that are actually pretty good; nothing like those nasty dried up things we had when I was a kid.
Hang in there!
Emily