So I finally remembered to write to my GI and he did actually write back. He said do not take diclofenac, take celebrex instead. It's another nonSteroid pain killer for arthritic pain and stuff like that. I got it and took the first capsul today and sure nuf, my knees are fine and I'm moving much more easily.
I always had lousy kneeds but they became noticably more painful after the colectomy, so I do think it is the colitis looking for another target, and hit my knees because it doesn't have my colon to mess with anymore.