The safety of osmotically acting cathartics in colonic cleansing

Nat Rev Gastroenterol Hepatol. 2010 Oct;7(10):557-64. doi: 10.1038/nrgastro.2010.136. Epub 2010 Aug 24.


Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate, combinations of polyethylene glycol and electrolyte lavage solutions (PEG-ELS), and magnesium citrate. All these preparations give adequate cleansing results and have similar profiles in terms of the frequency and type of mild to moderate adverse effects. However, serious adverse events, such as severe hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal function and water and electrolyte balance. The available evidence indicates that PEG-ELS-based products are the safest option. Magnesium-citrate-based, hypertonic products should be administered with caution to elderly individuals and patients who are prone to develop disturbances in water and electrolyte balance. Sodium-phosphate-based products can occasionally cause irreversible kidney damage and should not be routinely used in bowel-cleansing procedures.

Publication types

  • Review

MeSH terms

  • Cathartics / adverse effects*
  • Cathartics / pharmacology
  • Cathartics / therapeutic use
  • Citric Acid / adverse effects
  • Citric Acid / pharmacology
  • Citric Acid / therapeutic use
  • Colonoscopy / methods*
  • Humans
  • Kidney / drug effects
  • Organometallic Compounds / adverse effects
  • Organometallic Compounds / pharmacology
  • Organometallic Compounds / therapeutic use
  • Osmosis*
  • Phosphates / adverse effects
  • Phosphates / pharmacology
  • Phosphates / therapeutic use
  • Polyethylene Glycols / adverse effects
  • Polyethylene Glycols / pharmacology
  • Polyethylene Glycols / therapeutic use
  • Water-Electrolyte Balance / drug effects


  • Cathartics
  • Organometallic Compounds
  • Phosphates
  • Citric Acid
  • Polyethylene Glycols
  • magnesium citrate
  • sodium phosphate