Adequate cleansing is essential for reliable diagnostic and surgical colon procedures. Accuracy and safety depend on good preparation. Patient compliance is enhanced by simplicity and well-tolerated methods. Several methods are available. Diet and cathartic regimens utilize clear liquids or diets designed to leave a minimal colonic residue. Laxatives, cathartics and enemas are employed. Gut lavage solutions are osmotically balanced electrolyte lavage products. Oral sodium phosphate solutions and tablets are available and are attractive because of good efficacy with a small volume of administration. For colonoscopy and colon surgery preparation, these methods have been proven safe and effective. For barium enema X-ray, lavage requires an adjunctive agent such as bisacodyl to enhance barium coating. Overall, all regimens are well-tolerated. This review discusses the development and clinical experience with various colon cleansing regimens.