Acute phosphate nephropathy following oral sodium phosphate solution to cleanse the bowel for colonoscopy

Nephrocalcinosis is a term initially coined to describe the deposition of calcium crystals in the renal parenchyma resulting from prolonged states of hypercalcemia (ie, underlying malignancy, endocrinopathies, increased bone turnover, and increased calcium absorption).(1) More recently recognized is the deposition of calcium phosphate in the renal parenchyma with concomitant tubular injury that may occur with the use of phosphate-containing cathartics. This phenomenon was termed phosphate nephropathy. It is distinguished from the former by occurring in the absence of increased serum calcium levels, having distinct histopathologic findings, and often resulting in acute and persistent loss of renal function.(2,3) Acute renal failure secondary to phosphate nephropathy increasingly has been recognized as a complication after the administration of sodium phosphate solution in preparation for colonoscopy.(3) We report a case of acute renal failure secondary to phosphate nephropathy in a patient without preexisting renal disease after receiving intravenous radiocontrast for computed tomography and sodium phosphate for bowel cleansing. A renal biopsy showed diffuse renal tubular calcium deposition.