It’s one of the leading causes of cancer-related deaths in the U.S., but colon cancer's highly preventable if caught early with screening. Yet, for whatever reason, many are apprehensive about colonoscopy - an exam of the colon and rectum. One alternative is virtual colonoscopy. It requires the same laxative and low residue diet beforehand as the conventional procedure. But in this week’s Vital Signs, Dr. Cecelia Brewington of UT Southwestern Medical Center says virtual colonoscopy is less invasive, faster and there’s no sedation.