[Purple urine bag syndrome in elderly woman with nutritional supplements].

The purple urine bag syndrome is a rare entity which typically affects elderly women with prolonged urinary catheterization and weakening chronic diseases. Other predisposing factors are previous urologic pathology, immobility syndrome and chronic constipation. The purple color is due to the presence of high loads of bacteria with sulphatase--phosphatase activity which develop in an alkaline environment as well as the presence of other factors. In the case we present the administration of nutritional supplements containing tryptophan conditioned the generation of this syndrome.