The problem you have is due to indigestion
specially of carbohydrates &starchyfood also fats .you should take simple digestive tonic like Vitazyme or Cap. Pancreoflat 1 cap twice a day after food.
exercises along with Pranayam (Secially Agnisar ) will help in long run.
Please get your stools checked for amoebiasis
,worms.&take dr's advice for treatment if some problem is found.Drink boiled water only in ample