Purple urine bag syndrome

Background

Microbiology

• Providencia, Escherichia coli, Proteus mirabilis, and Klebsiella pneumonie

Pathophysiology

• Certain bacteria metabolise tryptophan to indole, which is later converted to indicant in the liver and excreted in the urine, where it is broken down by sulphatise- or phosphatase-producing bacteria into indigo (blue) or indirubin (red) in an alkaline environment such as the urine

Risk Factors

• Risk factors including constipation in women and chronic catheterization

Clinical Manifestations

• Purple discoloration of the urine
• Often associated with urinary tract infection