CRC is one of the most preventable cancers because its development in general follows an adenoma-carcinoma sequence. Adenomas are considered precursor lesions for CRC. Recent guidelines from USA, Europe and Asia Pacific region recommend CRC screening for average-risk asymptomatic individuals starting at age 50. Modalities such as guaiac-based fecal occult blood tests (gFOBT), fecal immunochemical tests (FIT), flexible sigmoidoscopy, and colonoscopy are among the acceptable options for CRC screening. Studies have shown that early detection and removal of colorectal adenoma by screening flexible sigmoidoscopy (FS) and screening colonoscopy with polypectomy reduce CRC incidence and mortality.