Hi,
Usage of antacids, staying away from fatty food items may help. It could also be due to digestion issues, overeating of rich food difficult to digest, lack of exercising, liver issues and effects of parasites or microorganisms on the digestive system can all cause intestinal gases. If simple life style changes does not help, he should see a GI doctor.
Solace
What kind of food is he eating? Maybe he just likes foods that are productive of a lot of gas.