Colonoscopy represents a very important diagnostic modality for screening for colorectal cancer, because it has the ability to both detect and effectively remove pro-malignant and malignant lesions. It is recommended by almost all international and national gastroenterology and cancer societies, as an initial screening modality or, following a positive fecal occult blood test, to be performed every 10 years in individuals of average risk starting from the age of 50. However, a significant problem is the so-called post-screening (interval) polyps and cancers found some years after the index colonoscopy. In order to reduce the rate of interval cancers it is extremely necessary to optimize the quality and effectiveness of colonoscopy. Bowel preparation is of paramount importance for both accurate diagnosis and subsequent treatment of lesions found on colonoscopy. The quality of bowel preparation could be significantly improved by splitting the dose regimens, a strategy that has been shown to be superior to single-dose regimen. A good endoscopic technique and optimal withdrawal time offering adequate time for inspection, would further optimize the rate of cecal intubation and the number of lesions detected. During the last years, sophisticated devices have been introduced that would further facilitate cecal intubation. The percentage of total colonoscopies is now super-passing the level of 95 % allowing the adenoma detection rate to be greater than the suggestive level of 25 % in men and 15 % in women. This review aims to provide the reader with the current knowledge concerning indications, usefulness, limitations and future perspectives of this probably most important screening technique for colorectal cancer available today.
Keywords: Colonoscopy; Colorectal; Colorectal cancer; Polyps; Screening; flexible Sigmoidoscopy.