Sodium phosphate (Na3PO4) is a phosphate of sodium. It is used as an emulsifying or thickening agent in food manufacturing. It is also available as an enema, working as a laxative to treat constipation. Sodium phosphate enemas are sold over-the-counter in the United States.
National Multiple Sclerosis Society's page on Sodium Phosphate enemas (http://www.nationalmssociety.org/Meds-SodiumPhosphate.asp)
