Purple urine bag syndrome in an elderly patient from Colombia.

A 71-year-old woman in a nursing home, with indwelling urinary catheter, bedridden, presented with a purple urine collector bag. The purple urine bag syndrome is a rare condition associated with the metabolism of tryptophan by overgrowth of intestinal bacteria. The purple color is formed by a combination of indigo and indirubin produced as a result of phosphatase and sulfatase enzymatic activity of bacteria on indoxyl sulfate, under alkaline pH of the urine. We present the second case of this syndrome reported in Colombia detailing the management of this rare syndrome associated with urinary tract infection. Several conditions should be considered in the differential diagnose of diseases that cause discoloration of the urine.