Preparation for Colonoscopy

Your colon must be completely empty for the colonoscopy to be thorough and safe. To prepare for the procedure you may have to follow a liquid diet for 1 to 3 days beforehand. A liquid diet means fat-free bouillon or broth, strained fruit juice, water, plain coffee, plain tea, or diet soda. Gelatin or popsicles in any color but red may also be eaten. You will also take one of several types of laxatives the night before the procedure. Also, you must arrange for someone to take you home afterward—you will not be allowed to drive because of the sedatives. Your physician may give you other special instructions. Inform your physician of any medical conditions or medications that you take before the colonscopy.

Fact sheets on other diagnostic tests:
ERCP Flexible Sigmoidoscopy Liver Biopsy	Lower GI Series Upper Endoscopy Upper GI Series

source: http://digestive.niddk.nih.gov/ddiseases/pubs/colonoscopy/index.htm