Maalox Anvanced is used to treat symptoms caused by too much acid in the stomach, such as heartburn, upset stomach, or indigestion. It is also used to treat symptoms of multiple gas such as bloating and feelings of pressure/discomfort in the stomach/intestines. Calcium carbonate is an antacid that works by reducing the amount of acid in the stomach. Simethicone works by breaking up air bubbles in the intestines.