UroNurse Episode 143: 

What Causes the Purple Color in Urine Bags?

Purple Urine Bag Syndrome (PUBS) is a rare phenomenon observed in patients with long-term indwelling urinary catheters, where the urine collection bag develops a purple discoloration. This striking color change results from the interaction between bacterial enzymes and metabolites in the urine. Specifically, bacteria such as Providencia stuartii, Proteus mirabilis, and Klebsiella pneumoniae produce sulfatase and phosphatase enzymes that deconjugate indoxyl sulfate, a metabolite derived from dietary tryptophan. This process leads to the formation of indigo (blue) and indirubin (red), which, when combined, impart a purple hue to the urine bag .​

 In this discussion, we will explore the findings from a recent survey that identified several factors increasing the risk of developing Purple Urine Bag Syndrome (PUBS). While PUBS is generally considered a benign condition, indicating bacterial colonization rather than an active infection, it may still require intervention. Addressing constipation, ensuring regular catheter maintenance, and monitoring for urinary tract infections are important strategies for managing and preventing potential complications associated with PUBS.

*The expert's opinions in this communication are personal and not representative of any organization. They are for informational purposes only, not official guidance. Viewers are advised to use their judgment, seek additional advice, and take responsibility for any actions based on these opinions.