2 year old with gas build up?

My best advice (I also have a 2 year old son) is to put him in a warm (not hot) bath tub. The warmth of the tub works better than a heating pad since it will provide all over comfort to his tummy and it's safer than a heating pad. You can also try putting a little baby oil on his tummy and giving his belly a little mage. This can relax his muscles and provide a level of comfort as well. My son has had multiple GI problems and I find that both these techniques work.