I use to be a big meat eater. Then I read a book called Self Healing Colitis & Crohns by David Klein. David Klein said he has never met anyone who recovered from Colitis & Crohns whilst still eating meat and other animal protein. After a bit of experimenting, I too discovered that meat caused me to have terrible flares. I am now trying to following a vegan diet. I say trying because it is hard to break habits of a lifetime overnight.
I had some chicken last week and have been regretting it ever since. From experiments, my main triggers appear to be meat, dairy, flour, nuts, alcohol, soy, lentils / legumes, beans / baked beans, rice, chocolate and sugar. From that list I am still having chicken, fish and alcohol every so often, but I am trying to wean myself off them because they keep giving me flares.
I am controlling things with a mainly vegan diet of fruit, vegetables, seaweeds, vegetable juices, smoothies, water, herbal teas, sprouted seeds, limited soaked nuts and coconut water. I am sort of following the principles set out in the book Self Healing Colitis & Crohns, but I am not as strict as I should be. I really must start being stricter. I am about 85% better than I was but think I could be 100% better if only I could maintain the diet.
I get my main source of protein from sunflower seeds, pumpkin seeds and flax seeds, quinoa, chia seeds, green leafy and other vegetables, limited soaked nuts and sprouted grains. It is really easy to get enough protein on a vegan diet as long as it is properly planned.