Gaviscon Double Action Suspension 300ml is an over-the-counter medication used to provide relief from the symptoms of heartburn, acid indigestion, and acid reflux. It works by neutralizing stomach acid and forming a protective barrier on top of the stomach contents to prevent acid reflux. This product is designed to offer double action to both neutralize excess acid and protect the esophagus from the harmful effects of acid reflux, helping to relieve discomfort quickly.