There are various methods available to cleanse the colon in preparation for diagnostic and surgical procedures. The popular options are diet and cathartic regimens, gut lavage and phosphate preparations. Each method has its own unique characteristics and safety profile. Diet and cathartic regimens are based on traditional methods of colonoscopy preparation and remain an acceptable and safe alternative for patients unwilling or unable to tolerate other bowel preparations. Gut lavage methods involve ingestion of 2-4L of osmotically balanced solutions containing polyethylene glycol, which have been shown to be safe and effective for colon cleansing, including for special patient populations with cardiac, renal or hepatic dysfunction. Phosphate preparations have also been shown to be safe and effective for colon cleansing and are generally better tolerated than counterpart gut lavage solutions. However, this method has safety concerns for some patients with cardiac, renal and hepatic dysfunctions.