The Digestive Process and Gas
First things first, there are different components of gas. “Some of it is from bacterial fermentation of the food that we eat, and some of it is air that we swallow,” explains Dr. Katz. When you eat, your stomach mechanically churns food, which enzymes and bacteria in your bowels break into smaller bits. Those bacteria release some carbon dioxide, hydrogen and methane gases during the process, which can build up in your stomach, small intestine and colon.
Malabsorption of certain compounds found in some foods — mostly carbs or sugars, including lactose, fructose, sorbitol, soluble fiber, raffinose and fructans — can also lead to gas, explains Katz. “Part of these sugars are going undigested into the colon, where they’re fermented. Gas results from the fermentation process.
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