You have taken many medications, and your problem is still persisting. Which means your problem is not simple. When you say you have gas problem it implies that you have abdominal distension after taking food. please let me know more about your problem because it may be something else. Do you have indigestion? Do you have cramping pain after meals? Do you feel pain in upper abdomen after meals? Does your problem arises after taking heavy meals? Answer to above questions will help me more to understand your problem.