Well I would think that you would have to go up in Prednisone if you are still flaring instead of tapering it already. But then it can be a pain trying to get off it later. Have you tried Rowasa enemas or Proctofoam? I had (some) better luck with those rectal meds than Canasa, I am not a fan of Canasa because they caused me more loose stool and problems than without.
Diagnosed with Left-sided UC in 1995 at age 15,
Prednisone, Rowasa & Hydrocort. Enemas, Proctofoam, Sulfasalazine, Asacol, Probiotics, Fish Oil, Aloe Juice, Canasa, Enotcort, Colazol, Anamantle, Remicade, etc... had 1 inch deep rectal ulcer 2004, put on Remicade, August 2007:Increased Remicade dosage-700mg every 6 weeks,diagnosed w/ Psoriatic Arthritis & Fibromyalgia Current meds: Clorazepate, Lomotil, Tylenol pm, Lyrica started 1/17/08, Flagyl 750 mgs started 4/2/08, Humira started 4/4/08