LAUSR

Since the invention of endoscopy in the 1800s, colonoscopy and flexible sigmoidoscopy have evolved into important tools in the diagnosis and treatment of lower gastrointestinal luminal diseases. These two modalities along with biochemical markers and widespread implementation of colorectal cancer (CRC) screening are responsible for the overall downtrend of CRC. However, this downward trend is not as robustly reflected in the right-sided CRC. It is thought that flat lesions in the right colon (sessile serrated polyp (SSA/P)), suboptimal colon preparation, differences in gender, and endoscopic techniques are some of the contributing factors accounting for this difference. In this review, we will summarize the most current literature and guidelines on CRC screening and surveillance. In addition, we will describe the recent advances in endoscopic CRC screening with emphasis on colonoscopy and flexible sigmoidoscopy and the changes they have brought to the CRC landscape in the US.