A kit for colonic cleansing includes a phosphate salt laxative, a flavorant, and an oral rehydration mixture. The flavorant includes aspartame and a citrate, and the oral rehydration mixture includes sodium and a glucose containing saccharide. The kit may be used for a colonic cleansing procedure by combining the phosphate salt laxative and the flavorant to provide a flavored laxative liquid, orally administering to a subject the flavored laxative liquid, and orally administering to the subject an oral rehydration liquid.