When the color of peritoneal dialysis effluent can be used as a diagnostic tool

Peritoneal dialysis (PD) effluent is normally transparent. A change in its appearance may be the first indication of an intra- or extraperitoneal abnormality which may or may not be related to the peritoneal dialysis technique itself. What diagnosis should be considered when PD effluent turns on red, orange, cloudy, milky white, green, yellow, purple or black in color? After review of the literature, we propose a differential diagnosis, as well as some management recommendations, for specific abnormal color presentations of the PD effluent.