Urinary ascites: an often overlooked diagnosis – key clinical clues for rapid recognition

Urinary ascites due to spontaneous rupture of the urinary bladder is a rare and frequently misdiagnosed condition that can mimic acute kidney failure through reabsorption of creatinine across the peritoneum. We report the case of a middle-aged woman presenting with abdominal pain, ascites and acute renal failure without an obvious cause. A significant discrepancy between creatinine-based and cystatin-C-based estimated glomerular filtration rate together with elevated creatinine in ascitic fluid confirmed pseudo-renal failure due to urinary ascites. CT scan with a late urography phase identified two small intraperitoneal bladder defects. The patient was successfully treated conservatively with continuous Foley catheter drainage for 6 weeks, resulting in complete recovery. This case highlights the diagnostic value of measuring creatinine in ascitic fluid, the role of cystatin C in suspected pseudo-renal failure and supports conservative management in selected cases of intraperitoneal bladder rupture.