While no medical procedure is fun, exactly, some can feel more intimidating than others. Root canals and mammograms may make the shortlist, but at the very top is the colonoscopy , a routine procedure in which a doctor uses a long tube with a tiny camera to examine your colon and rectum. Although you might get a colonoscopy at any age to diagnose or rule out various gastrointestinal conditions , the American Cancer Society recommends people with an average risk of colorectal cancer start screening at age 45.  If you have no idea what to expect, you’re not alone. “No one wants to talk about their colon health,“ says Dr. Fola May, director of UCLA’s Melvin and Bren Simon Gastroenterology Quality Improvement Program and an assistant professor at UCLA’s David Geffen School of Medicine.  But a colonoscopy doesn’t have to be shrouded in mystery.…