Acute phosphate nephropathy: a cause of chronic kidney disease

Acute phosphate nephropathy occurs whenever a patient with renal dysfunction is exposed to high doses of phosphate. Bowel purgative agents are a common source of high doses of sodium phosphate and are widely used as bowel preparation agents prior to colonoscopy due to their efficacy and tolerability. Oral sodium phosphate (OSP) preparations used to prepare patients for colonoscopy may be a cause of acute and chronic kidney disease (CKD). CKD associated with OSP agents is the result of nephrocalcinosis, or calcium phosphorus crystal deposition in the renal parenchyma leading to interstitial disease. It is often irreversible and progressive in nature. The authors report a case of CKD which presented with non-specific symptoms weeks after use of an OSP agent as part of a bowel preparation regimen. Renal biopsy confirmed nephrocalcinosis.