Celery and cabbage? Seriously? Ick!
Anyway, it might have been something you ate a couple of days ago, from what I understand.
49 year old female, diagnosed UC/pancolitis 1985, no surgery but much suffering.
Asacol/5ASA maintenance for 20+ years, usually 3 pills 2x day.
Currently tapering off presnisone from lingering flare;
August 2008 sought care of naturopathic doctor. Tested gluten intolerant and started gluten-free, soy-free, etc. diet which resolved flare. Also Replete probiotic, DGL (licorice root, slippery elm), Permeability Factors. Slow-release iron and B-12 shots for severe anemia.