Colonoscopy is considered the gold standard for colon cancer screening. In a recent study, however, 0.3% to 0.9% patients developed colorectal cancer within 3 years after removal of adenomas. Some reasons for the development of interval colorectal cancers include missed or incompletely removed lesions during the initial colonoscopy. Non-polypoid colorectal neoplasms are a potential contributor to the pool of missed lesions because they can be easily missed as a result of inadequate colon preparation or examination technique. This article discusses the methods that are useful to improve the quality of bowel preparation and examination technique.