Eating something like bread before drinking alcohol will line your stomach, also drinking water between each alcoholic drink will make it less likely that you are sick or get a hangover. Mixing milk and alcohol is more likely to make you sick as the milk will curdle.
Belching, also known as burping, is the act of expelling gas from the stomach out through the mouth. The usual cause of belching is a distended (inflated) stomach caused by swallowed air. The distention of the stomach causes abdominal discomfort, and the belching expels the air and relieves the discomfort.
There are two main causes of intestinal gas: swallowed air and gas that is produced as a by-product of the digestion of certain foods. Most swallowed air is released through burping. The rest is either absorbed in the small intestine or travels through the intestines to be released through the rectum.