Purple Urine Bag Syndrome.

The purple urine bag syndrome (PUBS) i.e. purple discolouration of urine, is an uncommon and alarming condition in patients with long term urinary catheterisation. Though the condition is benign, it should draw immediate attention to the possibility of an underlying urinary tract infection. The postulated hypothesis for this unusual event is probably a chemical reaction involving tryptophan from food in the gut. We report a case with this unusual and interesting phenomenon in a 65 year old female.