To assess the prevalence of cholelithiasis among chronic spinal spinal cord injured (SCI) male patients of the ACHS (Asociación Chilena de Seguridad). To evaluate statistically the prevalence of cholelithiasis among SCI patients compared to a control group and to the general male Chilean population. To assess the correlation between cholelithiasis in chronic SCI patients and usual risk factors such as age, obesity and diabetes mellitus