Gotta love those stinky bums!
Luke's gas was BA-AAAD for a very long time. My vet recommended Bean-o, the stuff for people. I've never tried it.
I switched my boy to the BARF diet and that cleared his gas (and an additional intestinal problem) right up. For more info on the diet you can check out the BARF forum. It is made up of meat, veggies (avoid cabbages, etc. that cause gas), eggs, yogurt, fish oils, etc. I have noticed a HUGE difference since switching. And as mentioned earlier the yogurt (acting as a probiotic) and fish oils help. And because it is all real food with no fillers they don't get as gassy. Higher quality kibble (Innova, Nutro, etc.) would also help. They can be $ though. The BARF diet can be home-made with ingredients you can find at home or the grocery store so it is very economical, even for a starving student like myself.
Good luck reducing your pooches gas!
Tamara