Gaviscon Extra Chewable Tablets works in two different ways – 1. Neutralises excess stomach acid to relieve pain and discomfort. 2. Gaviscon Extra forms a ‘raft’ over the stomach contents which helps prevent acid coming back up into the oesophagus (food pipe) As such it is effective at treating the classic symptoms of heartburn (a burning pain in the chest and mild acid regurgitation. Consult your doctor if you are over 40 years and have never suffered with heartburn and indigestion before.