These potent products offered an attractive alternative to the traditional pre-procedure bowel preps that often required one to drink a gallon of unpleasant-tasting liquid. Instead of drinking a gallon of liquid, one would only need to mix one small bottle of Fleet’s phospha-soda with their favorite juice.

The problem was that when used in the higher doses required to act as a bowel prep for procedures like colonoscopy, the products had the potential to cause kidney problems and even kidney failure. This side effect did not typically happen at the lower doses needed to use the product as a simple laxative.

Because of the risk of kidney problems, the products were yanked off of the shelves.  Similar products for bowel prep will still be available by prescription but will carry a special warning on the box. Many of the OTC products that were pulled from the shelf will be returning later this year, but the indications will be revised so they are only recommended at the smaller dosing as a laxative and not as a bowel prep.

Acute kidney failure due to the use of the product as a bowel prep is rare (only about 5 cases in one million doses). However, experts think that less overt kidney damage does take place and therefore stand by the recommendation that the product labeling be revised. They also recommend staying well hydrated when taking the product as a laxative to help keep kidney problems at bay.