Home Current issue Ahead of print Search About us Editorial board Archives Submit article Instructions Subscribe Contacts Login 
  • Users Online:
  • Home
  • Print this page
  • Email this page

 Table of Contents  
Year : 2016  |  Volume : 3  |  Issue : 4  |  Page : 133-135

Purple Urine Bag Syndrome: Are We Aware?

1 Department of Medicine and TB, Chest Clinic Moti Nagar, North Delhi Municipal Corporation, New Delhi, India
2 Department of Respiratory Intensive Care, Max Super Specialty Hospital, Saket, New Delhi, India
3 Department of Pathologist, Gen-X Diagnostics, Madhu Vihar, New Delhi, India

Date of Web Publication7-Nov-2016

Correspondence Address:
Sankalp Yadav
Department of Medicine and TB, Chest Clinic Moti Nagar, North Delhi Municipal Corporation, New Delhi - 110 015
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2394-2916.193518

Rights and Permissions

Purple urine bag syndrome is a rare, striking medical phenomenon observed in patients having indwelling urinary catheters having urinary tract infection. It is commonly observed in elderly patients having constipation and long-standing indwelling urinary catheters and indicates bacterial urinary tract infection. The purple discoloration of the urinary bag is reported to be due to the presence of indigo and indirubin pigment produced by tryptophan metabolism by Gram-negative Bacteria. The authors present a case of 67-year-old female with purple discoloration of her urine bag due to urinary tract infection caused by Klebsiella pneumoniae.

Keywords: Purple urine bag, urinary tract infection, urine discoloration

How to cite this article:
Yadav S, Rawal G, Singh A. Purple Urine Bag Syndrome: Are We Aware?. J Integr Nephrol Androl 2016;3:133-5

How to cite this URL:
Yadav S, Rawal G, Singh A. Purple Urine Bag Syndrome: Are We Aware?. J Integr Nephrol Androl [serial online] 2016 [cited 2023 Dec 11];3:133-5. Available from: http://www.journal-ina.com/text.asp?2016/3/4/133/193518

  Introduction Top

Purple urine bag syndrome (PUBS) is a rare medical phenomenon, in which the purple color of the urinary bag and/or catheter tubing, despite being benign, is a cause of distress for the treating physician and the patient. It is commonly seen in patients having chronic indwelling urine catheter and denotes urinary tract infection (UTI) caused by Gram-negative Bacteria which produce the enzymes: phosphatase or sulfatase. [1],[2] The purple color clears with the resolution of the UTI. Purple urine bag discoloration may be neglected due to its unawareness among the treating clinicians and thus, the treatment of UTI may not be initiated, which may lead to significant morbidity and mortality if it progresses to generalized septicemia.

This syndrome is commonly reported in elderly (commonly females) having constipation/gastroparesis and alkaline urine, along with chronic indwelling urinary catheters. [2],[3] We present an interesting case of an elderly lady who developed purple-colored urine bag. Although rare, this was the second case of PUBS, which was noticed by the authors; the first case reported earlier in an elderly male patient. [2]

  Case report Top

A 70-year-old woman, a known case of hypertension, diabetes mellitus, old-treated pulmonary Koch's and chronic kidney disease on medical management with a neurogenic bladder on Foley's catheter for 1 year (regularly changed every 3 weeks), arrived in the outpatient department (OPD) with the complaints of mild breathlessness, low-grade fever, constipation, and generalized weakness of 2-3 days duration. Her vitals: blood pressure 100/50 mmHg, heart rate 90/min, respiratory rate 16/min, and blood oxygen saturation of 94% on room air. Her systemic examination: Chest-bilateral scattered crepitation, heart sounds normal, abdomen-soft, distended, sluggish bowel sounds, neurological-conscious, and oriented with no focal neurological deficits. The patient also noted the purple color of her urinary bag [Figure 1]A for the past 2 days, although the urine in the measuring container was dark brownish color [Figure 1]B. There was no medication prescribed to the patient that could have caused this discoloration. The patient was managed on OPD basis and initiated on antibiotic (amoxicillin/clavulanate), antacids, laxative, and Foley's catheter, and the urine collection bag was changed. Her blood investigations showed mild leukocytosis, and urine routine showed a significant number of pus cells with an alkaline pH 8.0 and the culture later grew more than 100,000 colonies per milliliter of multidrug resistant Klebsiella pneumoniae. Her sputum culture also showed a similar growth. The antibiotic was modified according to the sensitivity and changed to oral levofloxacin. The patient was on regular follow-up and her urine and the purple color of the urine bag cleared up after about 4 days of antibiotic administration. The patient improved gradually and recovered with stable vitals. The occurrence of this phenomenon was attributed to the K. pneumoniae infection of the urinary tract.
Figure 1: (A) Purple discoloration of urine bag. (B) Dirty dark brown-colored urine in measuring container

Click here to view

  Discussion Top

The abnormal change in the color of urine has always baffled the mind of the treating clinicians and becomes a cause of anxiety among the patients. [4],[5] PUBS was first reported long back in 1978 by Barlow and Dickson. [6]

It is a benign/harmless condition which causes purple discoloration of the urine drainage bag and/or tubing (urine is usually brownish/turbid [Figure 1]B indicating infected urine) but warrants immediate attention for the treatment of UTI.


Tryptophan is one of the nine essential amino acids required by humans and is present in most of the protein-based foods or dietary proteins. Tryptophan is metabolized (deamination) by the intestinal Bacteria to indole, which is absorbed into the portal circulation and undergoes conjugation in the liver and is subsequently converted into indoxyl sulfate (indican). Indican is excreted in the urine and converted into indoxyl by the enzymes: phosphatase or sulfatase produced by Gram-negative Bacteria. This indoxyl is oxidized in alkaline urine to produce two pigments - indigo (blue) and indirubin (red) - which on reaction with the plastic (polyvinyl chloride) of the urine bag, result in the purple discoloration [Figure 2]. [7],[8]
Figure 2: Pathogenesis of purple urine bag syndrome

Click here to view

This phenomenon usually occurs in patients who are elderly (predominant in females) and have chronic constipation or gastroparesis which causes colonic bacterial overgrowth thus increasing the conversion of tryptophan to indole.

PUBS have been associated with several Gram-negative Bacteria producing the enzymes phosphatase or sulfatase which include K. pneumoniae, Escherichia coli, Pseudomonas species, Proteus species, Providencia species, Enterobacter species, and Morganella species. [7],[8],[9] Dehydration and chronic kidney disease are also risk factors as the serum concentrations of indoxyl sulfate (indican) have been found to be directly proportional to increasing azotemia. [10] The prevalence of PUBS has been reported globally in 8.3-16.7% of the patients with chronic urinary catheter use. [3],[11],[12]

  Conclusion Top

The uncommon purple color of the urinary bag can be alarming and distressing, but it indicates only the presence of UTI which can be recognized early and treated. The awareness of this syndrome needs to be spread among the clinicians so that expensive and the irrelevant investigations can be avoided and the treatment with antibiotics effective against the Gram-negative Bacteria (piperacillin/tazobactam, ticarcillin/clavulanate, ampicillin/sulbactam, ceftazidime, cefepime, levofloxacin, norfloxacin, moxifloxacin, meropenem, ertapenem) can be initiated early (even before the culture and sensitivity reports are available) on the basis of the suspicion. This can, therefore, help to prevent the adverse events and the mortality associated with the progress of the UTI to systemic septicemia.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Al Montasir A, Al Mustaque A. Purple urine bag syndrome. J Family Med Prim Care 2013;2:104-5.  Back to cited text no. 1
[PUBMED]  Medknow Journal  
Rawal G, Garg N, Yadav S, Wani UR, Shokeen P. Purple urine bag syndrome: An alarming and rare phenomenon of urinary tract infection. Int J Med Res Rev 2015;3:231-3.  Back to cited text no. 2
Su FH, Chung SY, Chen MH, Sheng ML, Chen CH, Chen YJ, et al. Case analysis of purple urine-bag syndrome at a long-term care service in a community hospital. Chang Gung Med J 2005;28:636-42.  Back to cited text no. 3
Rawal G, Garg N, Wani UR, Yadav S. Green urine: A rare benign side effect of propofol. Int J Med Res Rev 2015;3:136-8.  Back to cited text no. 4
Rawal G, Yadav S. Green urine due to propofol: A case report with review of literature. J Clin Diagn Res 2015;9:OD03-4.  Back to cited text no. 5
Barlow GB, Dickson JA. Purple urine bags. Lancet 1978;311:220-1.  Back to cited text no. 6
Hadano Y, Shimizu T, Takada S, Inoue T, Sorano S. An update on purple urine bag syndrome. Int J Gen Med 2012;5:707-10.  Back to cited text no. 7
Khan F, Chaudhry MA, Qureshi N, Cowley B. Purple urine bag syndrome: An alarming hue? A brief review of the literature. Int J Nephrol 2011;2011:419213.  Back to cited text no. 8
Dealler SF, Hawkey PM, Millar MR. Enzymatic degradation of urinary indoxyl sulfate by Providencia stuartii and Klebsiella pneumoniae causes the purple urine bag syndrome. J Clin Microbiol 1988;26:2152-6.  Back to cited text no. 9
Yang CJ, Lu PL, Chen TC, Tasi YM, Lien CT, Chong IW, et al. Chronic kidney disease is a potential risk factor for the development of purple urine bag syndrome. J Am Geriatr Soc 2009;57:1937-8.  Back to cited text no. 10
Shiao CC, Weng CY, Chuang JC, Huang MS, Chen ZY. Purple urine bag syndrome: A community-based study and literature review. Nephrology (Carlton) 2008;13:554-9.  Back to cited text no. 11
Lin CH, Huang HT, Chien CC, Tzeng DS, Lung FW. Purple urine bag syndrome in nursing homes: Ten elderly case reports and a literature review. Clin Interv Aging 2008;3:729-34.  Back to cited text no. 12


  [Figure 1], [Figure 2]

This article has been cited by
1 Purple Urine Bag Syndrome: Uncommon Clinical Entity Associated with Common Infection, Case Report
Muftah H. Elkhafifi
Al-Mukhtar Journal of Sciences. 2020; 35(3): 205
[Pubmed] | [DOI]
2 Purple Urine Bag Syndrome: a Rare Benign Condition Associated with Chronic Indwelling Urinary Catheter and Bacterial Infection in an Elderly Man
Santwana Verma,Kailash Chander Barwal,Digvijay Singh,Vineeta Sharma,Mayuri Shrivastava
Indian Journal of Surgery. 2019;
[Pubmed] | [DOI]
3 Purple Urinary Bag Syndrome can be a Presentation of Urinary Tract Infection
Prabhat Agrawal,Nikhil Purussnani,Maaz Farooqui
Journal of SAFOMS. 2018; 6(1): 77
[Pubmed] | [DOI]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Case report
Article Figures

 Article Access Statistics
    PDF Downloaded753    
    Comments [Add]    
    Cited by others 3    

Recommend this journal