Purple Urine Bag Syndrome: a Rare Benign Condition Associated with Chronic Indwelling Urinary Catheter and Bacterial Infection in an Elderly Man

  • Santwana VermaEmail author
  • Kailash Chander Barwal
  • Digvijay Singh
  • Vineeta Sharma
  • Mayuri Shrivastava
Case Report


Purple urine bag syndrome is a benign condition presenting with purple urine in a urinary bag in chronically catheterised elderly individuals. It is associated with constipation, chronic kidney disease and urinary infection with bacteria like Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Morganella morganii, Providencia, Enterococcus species and other bacteria that alkalinise the urine. Since co-occurrence of all factors is unusual, the condition is rarely encountered and rather unknown. In the aetiopathogenesis, tryptophan, an amino acid in the food, is metabolised by tryptophanase enzyme of infecting bacteria to indole. Indoxysulphate is produced from indole by hepatic conjugation and is excreted in urine. The microbes causing urinary infection that produce the enzyme indoxylsulphatase catabolise indoxysulphate to indoxyl. This in turn forms indigo, a blue substance, and indirubin, red in colour. The two mix to produce the colour purple thus accounting for purple urine. The condition is easily treatable but lack of awareness is a cause for alarm amongst the patient and the treating doctor. Thus, the present case will help create understanding of purple urine bag syndrome.


Purple urine bag syndrome (PUBS) Urinary catheter Infection Bacteria 


Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.

Ethical Approval

Informed consent was obtained from the individual participant included in the study. All procedures performed in the study were in accordance with the ethical standards of the ethical standards of the institutional and/or national research declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.


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Copyright information

© Association of Surgeons of India 2019

Authors and Affiliations

  1. 1.Department of MicrobiologyIndira Gandhi Medical CollegeShimlaIndia
  2. 2.Department of UrologyIGMCShimlaIndia

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