Abstract: Stimulant laxative in combination with an osmotic laxative produces safe and effective bowel and colon cleansing with a reduced volume of liquid input. Administering to a patient an oral stimulant laxative, such as bisacodyl, followed, after a biologically determined interval, by a reduced volume of a PEG in water solution cleanses the bowels and colon in preparation for diagnostic colonoscopy, without the profuse uncontrollable diarrhea that typically follows either ingestion of large volume isotonic ravages, or smaller volume hypertonic ravages.