A method of cleansing a mammalian GI tract is described and includes ingestion of polyethylene glycol (PEG) and magnesium citrate in a split-dose regimen. The split-dose regimen provides effective cleansing of the GI tract while minimizing discomfort and side effects to the patient A kit packaged with a first and second portion of PEG, and a first and second portion of magnesium citrate, and optionally simethicone is also provided.
