endoscopy

Examination of internal organs or tissues by an instrument allowing direct vision. An endoscope is equipped with an eyepiece, lenses, and its own light source to illuminate the field of vision. The endoscope used to examine the digestive tract is a flexible fibreoptic instrument swallowed by the patient.

There are various types of endoscope in use - some rigid, some flexible - with names prefixed by their site of application (for example, bronchoscope and laryngoscope). The value of endoscopy is in permitting diagnosis without the need for exploratory surgery. Biopsies (tissue samples) and photographs may be taken by way of the endoscope as an aid to diagnosis, or to monitor the effects of treatment. Some surgical procedures can be performed using fine instruments introduced through the endoscope. Keyhole surgery is increasingly popular as a cheaper, safer option for some conditions than conventional surgery.