For Relief of Occasional Acid Indigestion and Sour Stomach The use of antacids such as Calcium Carbonate for rapid relief of occasional heartburn has been well accepted. Calcium Carbonate works by neutralizing the acid produced in the stomach. It can, however, slow down the digestion of food when used alone because the enzymes secreted by the stomach only work at acidic pH. NOW Acid Relief with Enzymes contains digestive enzymes that work side by side with antacids, helping to encourage complete digestion of food, even in the presence of reduced stomach acid. NOW Acid Relief with Enzymes thus goes beyond typical antacids, delivering rapid relief from occasional indigestion, as well as digestive enzymes, in a delicious chewable tablet.