What is the purple urine bag syndrome (PUBS)?
Initially described in medical literature in 1978, PUBS is a rare condition associated with alkaline urine and UTIs caused by sulfatase- and phosphatase-producing bacteria (Providencia, E. coli, Proteus, Pseudomonas, Klebsiella) .
It is commonly observed in institutionalized elderly females with chronic indwelling catheters, who are also constipated.
The etiology remains unclear, although it is believed that indigo and indirubin pigments (which are metabolites of tryptophan) react with the synthetic material of the urinary catheter and bag and produce the purple urine.
Of interest, from a historical perspective, England’s “Mad” King George III was described by his physicians in 1812 to have a blue-tinged urine.
