For me, I feel it is usually related to my medications losing effectiveness or my foolishness in stopping my meds when I feel ok. I have also had a bad flare I blame on NSAIDs I was given by an Arthritis doctor, but of course cannot be certain that was the cause of the flare.
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 almost recto-vaginal fistula in 2004, put on Remicade, August 2007:Increased Remicade dosage-700mg every 6 weeks,diagnosed w/ Psoriatic Arthritis & Fibromyalgia Current meds: Clorazepate, Proctofoam HC, Glucosamine 500, Vitamin B, Lomotil, Tylenol pm, Lyrica started 1/17/08