What are the causes of a stomach ache, and how do you get rid of it?

Depends on cause: Many stomach aches will get better on their own with time. Gas pain, gallstone pain, reflux etc may last for 20 min to a couple hours and then resolve. Acid diseases (gastritis, gerd, ) may be temporarily relieved by Tums (calcium carbonate) etc. Any stomach ache that lasts longer than 3-4 hours or doesn't resolve with over the counter meds should be evaluated by your md.