I second the sodium comment. I am tapering down from 40mg right now and have been super
strict on the salt, and (knock on wood) have yet to get moon face. Some foods are also natural diuretics (sp?) like celery and watermelon if you can tolerate them. Your pain is felt for sure though! Moon face is one of the worst parts of taking pred.
Dx: UC in 1997 at 14 with pan colitis, but it hasn't been that far up since.
Meds: Asacol (400mg x12 daily)
6mp (50mg from Aug06 to Dec07)
Prednisone (40mg currently for flare)