The use of Fleet Phospho-soda as a bowel cleanser has been linked to a rare form of kidney damage known as acute phosphate nephropathy. The lawyers at Saiontz & Kirk are no longer investigating Acute Phosphate Nephropathy Lawsuits.  The information on this page is provided for information purposes only.

The use of oral sodium phosphate products, like Fleet Phospho-soda, Visicol and OsmoPrep, to clear out the bowels before a colonoscopy or other medical procedure, have been associated with the development of a rare but serious form of kidney injury known as acute phosphate nephropathy.

The Fleet Phospho-soda attorneys at Saiontz & Kirk, P.A. are  no longer investigating potential Acute Phosphate Nephropathy lawsuits for individuals who have been diagnosed with the kidney condition after using an over-the-counter Fleet Phospho-soda laxative at high doses for colonoscopy prep.

Symptoms of Fleet Phospha-Soda kidney problems could include:

  • Fluid Retention
  • High Blood Pressure
  • Irregular Heartbeat
  • Muscle Twitching
  • Seizures

In most cases the kidney damage from Fleet Phospho-soda is permanent and may require dialysis treatment, a kidney transplant or even lead to death.


Acute Phosphate Nephropathy, which is sometimes referred to as Acute Nephrocalcinosis, is a form of acute kidney injury which can develop within a few hours or up to 21 days after use of Fleet Phospho-soda or other oral sodium phosphate products to clean the bowels before a colonoscopy or colon surgery.

The kidney injury is associated with deposits of calcium-phosphate crystals in the renal tubules that can permanently impair kidney function.

Bowel cleansing with Fleet Phospho-soda or oral sodium phosphate prescription medications cause acute phophate nephropathy because they result in dehydration, decreased intravascular volume and hyperphophatemia, which increase phosphate levels in the renal tubules.

The decreased intravascular volume stimulates reabsorption of water from the renal tubules, which further increases the concentration of phosphate levels in renal tubular fluid and causes precipitation of calcium-phosphate crystals in the kidney.


In December 2008, the FDA warned that two prescription oral sodium phosphate drugs, Visicol and OsmoPrep, would require “black box” warnings about the acute phosphate nephropathy side effects, which is the strongest warning that can be placed on a prescription medication.

The prescription drug makers were also required to develop a risk evaluation and mitigation strategy and to distribute a medication guide with their products so that patients are informed of the kidney injury risk. They also must conduct post-marketing clinical trials to further evaluate the extent of the risk.

The same day the FDA issued their alert, C.B. Fleet Co. issued a Fleet Phospho-soda recall for their over-the-counter oral sodium phosphate laxative, which they had been marketing at higher doses as a bowel prep.  As a result of the acute phosphate nephropathy problems, Fleet removed the product from the market and indicated that it may be reintroduced as a prescription product at a later date if approved by the FDA.

The risk of suffering acute phophate nephropathy side effects from oral sodium phosphate products like Fleet Phospha soda is increased among:

  • Those over 55 years old
  • Those who suffer from dehydration, kidney disease, acute colitis or delayed bowel emptying
  • Those taking medicines that affect kidney function (like fluid pills, non-steroidal anti-inflammatories, drugs that lower blood pressure and medications used to treat high blood pressure, heart or kidney failure).