Yes, most of the immune system is in the gut. But that doesn't mean that diet plays a huge role for everyone. There are some of us who can eat just about
anything and it won't affect our UC. I didn't have a horrible diet before I was diagnosed and I'm 99.99% sure that my trigger was stress/depression/anxiety. And then my relapse was due to bc pills, not diet/stress/etc. And as pb4 said, diet hasn't been completely ruled out as a trigger but most research suggests that diet is solely not a factor for IBD. And the immune system isn't stupid, as pb4 also said; it gets the wrong signals and starts attacking our body. If IBD did not involve the immune system, then drugs like 6MP and Remicade wouldn't be helpful.
Female, Age 20
9 Asacol, Rowasa, 1000 mg Canasa, Proctofoam, Rifaximin 2/day
Digestive Advantage (Crohn's & Colitis), 1 Florastor, 50 mg 6MP, 1 Primadophilus reuteri, Remicade (7 infusions), 2.4 g Lialda, Forvia, 6 Colazal, 1 Anucort, Culturelle, Fish Oil, Calcium/Vit D supplement, 20 mg Prozac, VSL #3 DS, Turmeric