Surprising findings were published in the March 24 issue of the Archives of Internal Medicine which show that one of the most often suggested bowel cleaning preparations used by people who are about to have a colonoscopy can trigger both acute kidney failure and possibly long-term renal damage in otherwise healthy patients.
The risks in taking oral sodium phosphate solution and/or tablets is certainly real, although still a rare occurrence. In this article, author Dr. Anand Khurana, of the department of nephrology with Texas A&M University, says that "people should be very cautious in the use of these agents because of their potential of causing kidney damage." Especially when there is another product that can work just as well without this potential side effect.
The other popular prescription colonoscopy preparation -- polyethylene glycol solutions (PEG) -- was not the subject of the current study and does not appear to be associated with similar risks.
In 2006, the U.S. Food and Drug Administration put a black-box warning on the oral sodium phosphate solution, recommending that it be "used with caution" among patients with impaired kidney function due to its high phosphate content. However, the latest finding extends that concern to patients with no previous history of kidney trouble.
The problem stems from the fact that patients must ingest a bowel-cleansing liquid to clear out the colon, as well as refrain from eating solid foods the day before the procedure. The phosphate solution and tablets have been the preparations of preference because of convenience, as they are available without a prescription and require less clear liquid consumption than the polyethylene glycol solution.
Regardless of this inconvenience, if you are going to undergo a colonoscopy in the near future it would be wise to ensure you are using the bowel-cleaner with PEG, and with no potential to harm your kidneys or cause long-term damage.