[Conventional colonoscopy].

In the last 40 years colonoscopy has been the gold standard in diagnosis of conditions affecting the large intestine. We see its main disadvantages in the necessity for intestinal preparation and in the pain not infrequently experienced by patients who are not sedated. Widespread use of sedation has made it possible to improve patient acceptance in recent years. Complications of colonoscopy are rare, and even the removal of large polyps is regarded as a safe procedure. One of the main problems of colonoscopy is that a large number of far from trivial polyps--up to 20% in the literature--are overlooked. New developments, such as higher resolution videochips and chromoendoscopy, lead to a better diagnostic yield, especially of flat lesions. The rapidly developing sector of interventional colonoscopy in particular will ensure that colonoscopy continues to have an important place in the management of illnesses affecting the large intestine.