Do magnesium ions influence barium mucosal coating of the large bowel?

The aim of the present study was to verify whether the presence of magnesiu m in the colon limen at the time of the double-contrast barium enema (DCBE) examination changes the quality of barium mucosal coating. The two members of 38 pairs of patients undergoing DCBE with a standardised technique were randomly subjected to bowel preparation with sennosides and magnesium sulp hate, or sennosides and sodium sulphate. Mucosal coating, residual fluid an d colon cleansing were assessed independently by three radiologists. The nu ll hypothesis was tested by means of Wilcoxon's signed-rank test. Barium mu cosal coating was judged to be better in the members to whom magnesium sulp hate was administered (p = 0.0007). There was no difference in the amount o f residual fluids (p = 0.3198). Colon cleansing was judged to be better in the members to whom sodium sulphate was administered (p = 0.0166). These re sults demonstrate, in a simple way, that magnesium ions increase barium coa ting of the colon mucosa in vivo. The underlying mechanisms (increase in vi scosity of barium suspension through water subtraction owing to the hydroph ilism of magnesium ions, or interactions with the polysaccharide additives) need further investigation. A first clinical application could be the inte gration of magnesium ions in a newly designed isotonic electrolyte solution containing polyethylene glycol for the oral colon wash-out.