[Epidemiology and natural history of cholelithiasis].

Gallstone disease is relatively common, affecting approximately 15% of the population in Europe and North America, but it is benign since its natural history remains asymptomatic in nearly 80% of cases. The stones are predominantly cholesterol derived in 80% and pigmentary in 20% of cases. Recent epidemiologic studies using ultrasound examination have determined the factors favouring lithogenesis, in addition to those that are already wellknown, such as age, obesity, female gender, high blood triglyceride levels and multiparity, the risk is correlated with high, frequent variations in weight, with intake of certain drugs and with alimentary habits. In addition, physical exercise plays a protective role against the development of symptomatic gallstone disease.