Related Experiment Video
Updated: Aug 14, 2025

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection
Published on: October 12, 2017
Purple urine in Berdon syndrome: a rare finding in the clinic laboratory
Myriam Oliveira Rodríguez1, María Moreno Rodríguez1, Juan J Díaz Martín2
1Laboratory of Medicine, Department of Clinical Biochemistry, 16474Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain.
Introduction:
Purple Urine Bag Syndrome (PUBS) is a rare disorder seen in elderly persons, wherein the urinary bag and the tubing turn in to purple colour. It is usually seen in patients who are on urinary catheters for a long time. It consists of a change in the colour of the urine that turns purple in a very specific context.
Case Report:
We report the case of a paediatric female patient with Berdon Syndrome with symptoms consistent with urinary tract infection and purple urine discolouration. Urine test revealed leukocyturia and bacteriuria.
Discussion:
Several risk factors have been proposed regarding this syndrome. Among them the commonest are female gender, advanced age, kind of diet (increased dietary tryptophan), alkaline urine and diverse situations that leads to urinary retentions which allows bacteria to work on their substrate for a longer time. Although it is a process that is not associated with gravity, recognizing it is important as treatment is simple and can minimize patient and family distress.
Related Concept Videos
Urine Studies I: Urinalysis
Serum Studies: Renal Function Tests
Physiology of Urine Formation
Glomerular Filtration
The first stage in urine formation is glomerular filtration. Each kidney contains approximately 1 million nephrons, the functional units of filtration, with a...
Acute Pyelonephritis II: Diagnostic Studies and Management
Nephrotic Syndrome II : Assessment and Medical Management
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...

