Have you heard of the term 'Lactose Intolerant"? The dairy might be the culprit if you cannot break down the sugars, and adding enzymes that break down dairy should help.
Bacteria causes gas while it tries to break down food in the intestines. You should consider doing a colon and parasite cleanse to rid your body of undigested foods that might be adding to the problem.
Candida feeding on the diary is another issue you need to look at. Check the candida boards for suggestions.
You should try to avoid dairy for at least a week and see if your symptoms change. If they do, then you have found the culprit, but will then have to determine if it is a digestive or candida problem. The other options is to eat only one kind of vegetable daily adding a new veggie each day until you start to experience symptoms again, so you find the veggies that cause gas in you.