The stones are formed from bile salts, lecithin, and cholesterol . They may be as small as a grain of sand, or become as large as an inch in diameter. If symptoms are present, they are similar to acute cholecystitis , or cholangitis .
Symptoms usually occur only when the stones block one of the ducts in the biliary system .
Cholelithiasis is very common with the incidence 1 out of 1,000 people. The prevalence is greater in women, native Americans, and people over 40. There is no known way to prevent gallstones. If you have gallstone symptoms, eating a low fat diet and losing weight may be helpful in controlling symptoms. Bile salts taken orally may dissolve gallstones in those with a functioning gallbladder, but the process may take 2 years or longer, and stones may recur after the therapy is discontinued.