Belching is a very normal way that your body expels excess air from your stomach. There are many reasons you may swallow excess air: chewing gum, drinking carbonated beverages, smoking, talking fast, or talking while you eat.
Flatulence is also called gas and refers to the passing of gas through your rectum. The gas can be caused by either swallowed air or the breakdown of food during digestion.
In some cases, gas may build up in your stomach and intestines and cause bloating. This means you have a feeling of fullness or sometimes, pain. The symptoms may go away if you pass gas or have a bowel movement.
Belching, bloating, and gas/flatulence can be natural and expected to a degree. Talk with your physician if your symptoms are persistent and significantly bothersome.