Baked beans are a good source of protien but for many of us can cause alot of gas and pain. Good sources of protien are chicken breast, salmon or other types of fish(not deep fried), eggs, beans(too much will cause bloating and gas). Carbs that don't cause alot of problems rice and rice products. Cooked veggies are good, salad is good but can cause bloating if the colon is irritated, might be hard to digest. Bananas are very tollerable, some fruits are high in sugars which can cause problems. Try to cut out your fast food for a month if possible, lactose is used as fillers in many foods. I find that my gut is so bloated and in pain after eating at certain fast food places. I avoid them they also cause diahrea.
Probiotics that many of us on the UC forum take is the Renew Life Ultimate Flora Critical Care 50 billion bacteria per capsule. I take it morning and night on an empty stomach. I also alernate with one called Bio-k Plus it comes in a yogurt like container(boxes of 6 or 15)50billion bacteria per container.