Maalox is a bran name antacid containing Aluminium hydroxide and Magnesium hydroxide to neutralize or reduce stomach acid. It helps relieve symptoms of excessive stomach acidity in patients with indigestion, heartburn, gastroesophageal reflux disease (GERD {US} or GORD {UK}), or stomach or duodenal ulcers. In large doses, it can act as a laxative.