Use of certain antibiotic medications. If your child is affected by some infection, the medications that you have been giving him may trigger excess formation of gas
Lactose intolerance. Your baby may be intolerant to lactose, which is commonly found in milk and most milk products.
Diet changes. You may have introduced your kid to some new foods which may be causing excess formation of gas.
Several times, children may also swallow large amounts of air while eating or drinking. It causes increased flatulence.