You can get food sensitivity testing. It was $300 at the Naturopathic doc.
But I didn't need it to know that iceberg lettuce tears me up. I can do small salads of romaine. I'm afraid to eat raw spinach, even though it's been so long I don't even remember what it did to me.
49 year old female attorney, diagnosed UC/pancolitis 1985, no surgery but much suffering.
Asacol/5ASA 6x400 mg maintenance for 20+ years; use prednisone & Rowasa for flares.
August 2008 sought care of naturopathic doctor. Food sensitivity test showed wheat/gluten, other intolerances; started diet without gluten, soy, dairy, tomato etc. Replete$$ probiotic powder, then Forte, now a stronger one (50 billion). Doing much better, but still having some bad days.