The consumer advocacy group Public Citizen is warning patients that certain bowel-cleansing products used prior to colonoscopies are linked to chronic kidney failure, according to two new research studies.

Recent research published in the Journal of the American Society of Nephrology shows that products containing sodium phosphate are an under-recognized cause of chronic kidney failure in the United States. Visicol, a prescription oral tablet, and Fleet Phospho-soda, a non-prescription product, both contain sodium phosphate. Potential factors that may contribute to the development of chronic kidney failure in patients exposed to sodium phosphate include inadequate hydration, a history of high blood pressure, and the use of nonsteroidal anti-inflammatory drugs, or NSAIDs. Common NSAIDs include aspirin and ibuprofen.

A second study from the Columbia College of Physicians and Surgeons in New York found 31 patients who had kidney damage consistent with phosphate toxicity. The researchers reviewed all of the kidney biopsies that they received between January 2000 and December 2004. Of the 31 patients, 20 took oral phosphate solutions prior to having colonoscopies.

Source: Carolyn Susman, “Bowel-cleansing products, kidney failure are linked,” South Mississippi Sun-Herald, March 15, 2006.