How can make gas move that is trapped in your sides and stomach

Sources of gas?: Air in the digestive tract may come from a variety of sources--maldigestion due to enzyme deficiency (ex. Lactose intolerance) or food intolerance (ex. Gluten sensitivity), fermentation by gut bacteria (as with bacterial overgrowth syndrome or changed flora after antibiotics), altered GI tract motility, excessive air swallowing, as well as inflammatory and infectious causes. Would test for these.