I'll share what my mom did for me while I was in a flare (keep in mind I was 9 years old and not really a picky eater).
Diet: My GI at the time had her basically follow a low residue diet also similar to the BRAT (bananas, rice, apple sauce and toast) diet. Basically nothing fried, nothing spicy (minimal pepper, I liked spicy things and this was as close as I could get, white pepper may work better since its a fine powder rather than larger pieces that you get with ground black pepper), no skins or seeds on veggies or fruits, no fat or skin on meats, minimal oil or butter, no nuts (a little peanut butter was ok) and no raw fruits (bananas were ok) or vegetables.
Meals would mostly bake a chicken breast (or white fish with butter and lemon) with a little seasoning (like salt, little pepper, and maybe onion or garlic powder), have rice on the side with a little butter on top and a colorful vegetable like spinach (cooked with, lemon, salt, butter). I would also eat brussel sprouts, squash, sweet potatoes (baked) etc. All veggies were steamed so you don't lose all the nutrients like you do with boiling them. The more colorful they are, the more nutrients they contain (if you're going to go with beets, try to get the yellow or orange beets cause red ones might freak you out).
Snacks were like toast with a little butter and jelly (seedless always), pudding, apple sauce, toast with butter cinnamon and sugar, and jello etc.
Beverages were tea (I was fine with any kind but camomile was my favorite), little juice, water and sometimes soda but no more than 8 ounces (I got some like once or twice a week).
Things I didn't digest well were corn, peas, green beans, nuts, seeds etc.