Purple Urine Bag Syndrome in End-Stage Renal Disease: Recognizing the Unexpected.

Purple urine bag syndrome (PUBS) is an uncommon but striking phenomenon seen primarily in elderly patients with neurogenic bladder and long-term indwelling Foley catheters. In some cases, it may be the only clinical manifestation of a urinary tract infection (UTI). The characteristic purple discoloration results from metabolic byproducts such as indigo and indirubin, formed through bacterial enzymatic activity in the urine. Though benign in itself, the condition can cause significant anxiety in patients, caregivers, and healthcare providers unfamiliar with it. We present the case of an elderly female dialysis patient with a neurogenic bladder and chronic Foley catheter use, whose only sign of recurrent UTIs was the development of purple urine. Notably, there is only one other reported case of PUBS in a patient undergoing dialysis, highlighting the rarity of this presentation. Through this report, we aim to underscore the importance of recognizing PUBS as a potential early indicator of infection, in order to facilitate prompt management and prevent unnecessary physical and psychological stress.