Efficacy and safety of sodium phosphate tablets compared with PEG solution in colon cleansing: two identically designed, randomized, controlled, parallel group, multicenter phase III trials

Gastrointest Endosc. 2001 Dec;54(6):705-13. doi: 10.1067/mge.2001.119733.


Background: Liquid purgatives for cleansing before colonoscopy often are poorly tolerated. A sodium phosphate tablet has been developed to provide equivalent efficacy with better patient tolerance. These 2 studies compare the safety, efficacy, and patient acceptance of the tablet (Visicol) to a polyethylene glycol (PEG) solution in adults undergoing colonoscopy.

Methods: Two identically designed, randomized, investigator-blinded, multicenter trials were performed. The primary efficacy variable was the overall quality of colon cleansing. Patient tolerance was assessed in terms of compliance with the dosing regimen. Safety assessments included recording of adverse events and changes in biochemical tests, electrocardiogram, and vital signs.

Results: Eight hundred forty-five patients participated in the studies; 420 took sodium phosphate tablets and 425 took a PEG solution. The 2 methods of preparation were equivalent in the overall quality of colon cleansing, cleansing in the right colon, and the frequency of inadequate preparation. Overall cleansing was excellent or good in 84.3% of patients in the tablet group and in 76.7% in the PEG group. Patient compliance was greater in the tablet group. There were also significantly fewer GI side effects in this group.

Conclusions: Sodium phosphate tablets, compared with PEG solution, produce equivalent colon cleansing, are associated with fewer GI side effects, and are better tolerated by patients.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase III
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Atrial Fibrillation / chemically induced
  • Colonic Diseases / diagnosis
  • Colonic Diseases / surgery
  • Colonoscopy / methods
  • Double-Blind Method
  • Female
  • Gastrointestinal Diseases / chemically induced
  • Humans
  • Male
  • Middle Aged
  • Phosphates / administration & dosage*
  • Phosphates / adverse effects
  • Polyethylene Glycols / administration & dosage*
  • Polyethylene Glycols / adverse effects
  • Preoperative Care / methods*
  • Sensitivity and Specificity
  • Solutions
  • Tablets
  • Therapeutic Irrigation / methods*
  • Treatment Outcome


  • Phosphates
  • Solutions
  • Tablets
  • Polyethylene Glycols
  • sodium phosphate