consider taking a probiotic supplement. this has seriously helped me with bloating and outright abdominal pain after eating. most HFS should have them.
ginger tea helps me out a ton with nausea, and it seems to help a little with bloating/gas. it will also help spark a bit of appetite if i grab a cup before a meal. you could also try ginger supplements or other ways of using ginger, too.
the other thing, like kreeli said, is to eliminate all possible culprits and then add in things one at a time (remember all the one-variable science experiments from way back when?) and see what happens. when i get "flare-ups", i usually go for stuff that's rice-based -- cream of rice cereal, other warm breakfasty rice dishes, even rice pudding (use rice milk when you make em instead of soy, just in case that's one of the culprits.)
one more thing. some of us (like me) react to many things -- stress, change, whatever -- with our gut. try to make mealtime as pleasant as possible. make it relaxing, and enjoy it -- even if you are alone, light a candle, clean up the kitchen/dining room, make things peaceful. don't watch the news, debate serious stuff, etc. by promoting a positive eating atmosphere, a lot of times it helps promote better digestion for me.