Study as to the cause of gallstones has been extensive since they were first reported, in the fourteenth or the fifteenth century. Early thought was purely speculative, but since the time of Naunyn a mass of clinical and experimental data has been accumulated. A multitude of theories have been propounded, none of which is adequate to explain the whole problem.
A fundamental difficulty has been the failure to recognize that the conditions which determine the formation of biliary calculi are multiple and complex. In addition, there are several varieties of gallstones. According to the classification of Naunyn there are pure cholesterol stones, calcium bilirubinate stones, and the common "mixed" gallstones. Each of these may be determined by the combination of a different set of circumstances. In the series of observations we shall discuss, only the pure cholesterol stone and the common "mixed" gallstone will be considered.
The cause of gallstones