<P> An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach . </P> <P> Antacids are available over the counter and are taken by mouth to quickly relieve occasional heartburn, the major symptom of gastroesophageal reflux disease and also indigestion . Treatment with antacids alone is symptomatic and only justified for minor symptoms . </P> <P> Antacids are distinct from acid - reducing drugs like H - receptor antagonists or proton pump inhibitors and they do not kill the bacteria Helicobacter pylori, which causes most ulcers . </P> <P> Versions with magnesium may cause diarrhea, and brands with calcium or aluminium may cause constipation and rarely, long - term use may cause kidney stones . Long - term use of versions with aluminium may increase the risk for getting osteoporosis . </P>

What are antacids explain their role in providing relief from stomach ache