Colorectal cancer (CRC) is the second most common cause of cancer-related death in the Western world, with 500000 deaths per year worldwide. Colonoscopy is accepted as a primary CRC screening tool in many countries. As a preventative procedure, its main purpose is to enable the early diagnosis of CRC at a curable stage and to identify and remove pre-malignant adenomas. Cecal intubation is associated with an increased detection rate of advanced neoplasia, as 33-50% of advanced neoplasia is located in the proximal colon. Complete colonic evaluation is therefore a well-recognized measure of colonoscopy quality control. Cecal intubation rates of ≥ 90% of all colonoscopies in routine clinical practice and ≥ 95% in screening colonoscopies are recommended. Unfortunately, the cecal intubation rate in daily clinical practice is often lower than the target of ≥ 90%, with reported percentages varying from 76.9% to 98.4%. This means that after an incomplete colonoscopy, malignant and pre-malignant lesions may be missed if further investigation is not pursued. Several explanatory factors for incomplete colonoscopy have been described. After an incomplete conventional colonoscopy, patients are required to undergo another test to complete the visualization of the colon. Options for incomplete examinations because of anatomic reasons include both radiologic and endoscopic means.