The field of colonic diagnostic and surgical procedures is hampered by the lack of optimal means available to cleanse the colon. A compromise between convenient, distasteful, solid or low volume, hyperosmotic solutions which cause considerable fluid and electrolyte imbalances in patients and large volume, difficult to consume, iso-osmotic solutions has had to be made heretofore. This invention describes a low volume, hyper-osmotic solution consisting of sulfate salts with and with out polyethylene glycol. Unlike prior art, this composition is useful for the cleansing of the bowel and, in lower volumes, as a laxative, without producing clinically significant changes in bodily function.