Standard white light endoscopy involves the passage of a thin, flexible camera into the colon from the anus. Although standard white light endoscopy can detect most polyps and precancerous areas in the gastrointestinal tract and colon, many studies have shown that even the most experienced doctors, under optimal conditions, can miss up to 15-25% of precancerous areas. Thus, there remains a clear need to develop new methods of improving standard white light endoscopy. We are investigating whether indocyanine green (ICG) can serve to highlight areas which are precancerous when the colon is visualized with a special cameral which shines fluorescent light. Information from other studies suggests that this ICG agent may help to visualize blood vessels flowing to precancerous areas in the colon. We are looking at the ability of ICG, in combination with an endoscope which shines fluorescent light, to visualize precancerous areas in the colon.