Because it contains antacids, a product like Gaviscon Peppermint Liquid Sachet 10ml x5s (Box) relieves heartburn and indigestion.
An antacid is a medication that reduces stomach acidity and is used to treat stomach discomfort that is associated with excess stomach acid such as acid reflux.
They are available in liquid or chewable tablet form and can be purchased without a prescription or as over-the-counter medication.
Other substances, such as alginate (which coats your gullet with a protective layer) and simethicone, are also found in some antacids (which reduces flatulence). Gaviscon product contain sodium alginate which was extracted from the cell walls of seaweed.