Since the publication of our article on colonoscopy preparations,1 which compared polyethylene glycol electrolyte solutions (GoLytely, and others) with sodium phosphate (Fleet Phospho-Soda, and others), some readers have told us that we should have included a combination of a magnesium citrate solution with bisacodyl tablets (Evac-QKwik, and others) as an alternative. In one study, such a preparation offered better cleansing and patient tolerance than a sodium phosphate regimen.2

1. Colonoscopy preparations. Med Lett Drugs Ther 2005; 47:53.

2. M Delegge and R Kaplan. Efficacy of bowel preparation with the use of a prepackaged, low fibre diet with a low sodium, magnesium citrate cathartic vs. a clear liquid diet with a standard sodium phosphate cathartic. Aliment Pharmacol Ther 2005; 21:1491.