Maybe you've had this scenario described to you by a customer: About an hour after dinner she begins to notice an uncomfortable sensation in her abdomen. She says the pain is cramplike, builds in intensity and shoots back toward her right shoulder blade. Nausea follows. She takes an antacid but wonders whether she has symptoms of appendicitis, food poisoning or an ulcer. A visit to her doctor reveals that she is actually suffering from complications of cholelithiasis, also known as gallstones.