IMAGING THE DIGESTIVE SYSTEM: Colonoscopies are viewed as the "gold standard" for catching colorectal cancer before it has a chance to take root and spread. Gastroenterologists recommend that men and women over the age of 50, without a risk of colon cancer, get a colonoscopy every ten years, while those at high risk should receive them earlier and more frequently. During a colonoscopy, physicians visually examine the lining of the colon and rectum with an endoscope (small camera). The "scope" is passed through the rectum and into the colon to directly examine the lining of the lower digestive tract -- a full five feet of twists and turns. Upper endoscopies are used to examine the esophagus, stomach and the upper part of the small intestine (the duodenum). The endoscope described in this story can also be used to examine other organs in the digestive tract, at a greater magnification than previously possible.
WHAT ARE LASERS: "Laser" stands for Light Amplification by Stimulated Emission of Radiation. The term describes any device that creates and amplifies a narrow, focused beam of light where the photons are all traveling in the same direction, rather than emitting light every which way at once. An opposite example would be a flashlight, where the atoms release their photons randomly shining light in all directions. Laser light contains only one specific color, or wavelength. The type used in this segment, the confocal laser endomicroscope, produces blue light.