As my dearly departed sister-in-law once remarked...everything causes gas!
The trick is to combine your foods so that they create the least amount of gas possible...I had a lot of success with a dissociated diet where I never ate carbs with protiens and kept my fruits to seperate meals...I ate fruit and drank fruit juices in the morning and for 4pm snack, ate either meat/fish/chicken etc with veggies for either lunch or dinner and had carbs (rice, bread, pasta, potatoes) with veggies for the other meal...it was a system that was really pouch friendly, kept things digesting well and flowing smoothly and allowed me to eat a lot more foods than I had ever been able to eat previously...I kept to it for about 20yrs and it worked wonders (didn't meant that I was gobbling a cheese pizza every now and then) but most of the time I kept to it...Even now I automatically I go back to it as soon as I have a problem, wish to loose weight or feel 'pouchy'...
I avoid milk and too much cheese but eat yoghut and similar products...plus I do really well on goat cheese...
It is when I overdo the diary that I have the most gas and cheese sandwiches are a no-no but otherwise gas is no longer a major problme in my life.
Sharon