We have a warning from KidneyNotes.com. Danger to Kidneys May Lurk in Some Sodium Phosphate Preparations for Colonoscopy. Quoting from The New York Times:
No one disputes that colonoscopies save lives. But recent research has prompted concern that in rare instances certain popular bowel-cleansing preparations that patients gulp down the day before a procedure can severely damage the kidneys. The products are oral preparations made with sodium phosphate and they include Visicol tablets, sold by prescription, and over-the-counter solutions like Fleet Phosphosoda and store-brand versions that contain the same active ingredients.
A team of doctors from the Columbia College of Physicians and Surgeons recently reported 21 cases of acute kidney failure from such products, including three that led to permanent dialysis and one to a kidney transplant. The study appeared in the November issue of The Journal of the American Society of Nephrology.