All of the following are true about brown pigment gall stones except

Answer- B. More common in Western countriesBrown stonesAre composed of calcium salts of unconjugated bilirubin with varylng amounts of cholesterol and protein (eg. Calcium bilirubinate, calcium palmitate and calcium sterate).Are typically found in Asia.Brown stones are rare in gallbladder. They form in bile duct and are related to bile stasis and infected bile.Gram-negative bacteria (paicularly E. coli) secretes p -glucoronidase which deconjugates the soluble conjugated bilirubin. The free unconjugated bilirubin precipitates and combines wtih calcium and bile to form brown pigment stones. They form whenever static foreign bodies are present in the bile duct, for example 'stents' or parasites such as Clonorchis sinensis and Ascaris lumbricoides.