This medicine has both a laxative and an antacid action and helps relieve the symptoms of stomach upsets, indigestion, and over production of bile. This medicine contains three main ingredients. Sodium bicarbonate and citric acid are antacids which work by neutralising excess acid and help relieve the symptoms and discomfort associated with stomach upsets and indigestion. Magnesium sulphate has a laxative action. This medicine is available as an effervescent powder which has to be dissolved in water before taking. Read the leaflet to confirm if this medicine is suitable for you and which dose is needed.