Everyone will have different takes on food recommendations. I find lean and tender white meat of chicken and turkey, scrambled eggs, soft-cooked carrots, greenbeans and grean peas, canned pears and peaches and very ripe bananas to all be safe foods for a flare. Vegetables should be well-cooked and peels should be removed from both veggies and fruits. Blended veggie soups are ideal. Udo's, olive and flax oils along with nut butters and avacadoes will add healthy fats.
Some foods that seem to cause problems are alcohol, caffeine, carbonated drinks, fried foods, hot and spicy foods, dairy products and anything with MSG or carrageenan. Sugar alcohols can really do a number on sensitive digestions, too.
Probiotic supplements can help restore a healthy gut ecology. If you've taken broad spectrum antibiotics, the meds indiscriminately kill both bad and good gut bacteria. However, you may want to proceed cautiously with probiotics if you're in a bad flare with alot of inflammation.