The American College of Gastroenterology, based on two recent studies, is recommending patients split their colonoscopy preparation into two parts, one the evening before and the other about six hours prior to the exam, as it leads to clearer colonoscopy views and better results. The presence of residual stool will make it harder for the colonoscopist to identify abnormal growths that could develop into cancer.
It is important that you ask your doctor about which preparation may be most suitable for you. It is equally essential that you follow his or her instructions so to attain a clean colon for your colonoscopy. "Cheating" during preparation time, for example, by eating solid foods or not completing the preparation will be a set up for a poor colon cancer screening. Better visualization will make colon polyp detection much easier and safer. It will also reduce the likelihood of missing any abnormal growths in the colon.
Your doctor should explain to you all of the aspects of colonoscopy including preparation, length of the test and the types of sedation that are available. Colon cancer screening with colonoscopy begins at age 50 and at age 45 for African Americans. Annual stool testing for the presence of blood begins at age 40 and is performed annually.