Enteral feeding tubes represent convenient avenues for medication administration and electrolyte replacement. The frequent association of medication therapy with gastrointestinal disorders during enteral nutrition prompted this evaluation of medication and electrolyte solution osmolality. It is concluded that the hypertonicity of electrolyte replacement solutions and various medications may cause gastrointestinal intolerance in patients. Electrolyte supplementation by parenteral means or by appropriate dilution and mixture with an enteral formula is preferable to bolus administration of undiluted solutions via the feeding tube. Routine admixture of medications such as antibiotic suspensions to enteral formulas cannot be recommended at this time pending specific study of drug compatibility and availability from enteral tube feeding systems.