Does prilosec help with gall stones?

Not per se: Prilosec is an antacid, it decreases the formation of acid and reduces symptoms such as reflux or heartburn. Gallstones cause symptoms when they block the egress of bile from the gallbladder, sometimes the symptoms overlap, but they are fundamentally different problems. Also some patients will have both reflux and gallstones, in which case Prilosec and other antacids may relieve reflux symptoms.