I heard gum (maybe candy also) gives people with the lap band gas, because it is like you are swallowing air as you chew, and so its like drinking carbonated drinks, something we are not suposed to do with the band. i think it could strech the pouch. not sure about this, thats just what i heard.
maybe the mouth wash can help, or try different foods and tasets that you are able to have, depends on what stage in the plan you are in (liqueds, soft foods, etc.)
if its really a problem, maybe the doctor or the nutritionist might be able to suggest something. good luck