FDA issues "stern" safety warnings on Salix brand Visicol and OsmoPrep bowel cleansers

"When used for bowel cleansing, these products have the same risks as prescription" drugs, the FDA said in a statement.

The agency advised consumers not to use any of the over-the-counter products for bowel cleansing. While nonprescription products cannot receive boxed warnings, FDA officials said they hope to update labeling on the dozens of over-the-counter phosphate drugs by next spring.

The FDA first warned doctors and patients about potential kidney risks with the medications in 2006. A petition submitted to the agency last September called on regulators to place a boxed warning on the drugs.