Purple urine bag syndrome: a truly harmless sign?

Purple urine bag syndrome is an uncommon condition that describes the purple discolouration of a catheter bag and tubing. It mainly affects patients with limited mobility who have long-term catheters. Although benign in nature per se, its presence can alarm both patient and practitioner unfamiliar with the syndrome. Here, we describe two cases of asymptomatic patients who both presented to outpatient clinic with the characteristic purple discolouration of their long-term catheters and tubing. The report discusses the pathophysiology of the syndrome and initial investigation and management. Although the syndrome is considered benign, it may signify occult urine tract infection. This should not be ignored even if the patient is asymptomatic, given the likely co-morbidities of the patients affected. Healthcare professionals - particularly urologists and geriatricians - need to be aware of this unusual syndrome so as to initiate appropriate investigation and possible treatment as soon as possible.