Endoscopy is a procedure that enables the examiner (usually a gastroenterologist) to examine the oesophagus (swallowing tube), stomach and duodenum (first portion of small bowel) using a thin, flexible tube through with the lining of the oesophagus, stomach and duodenum can be viewed on a monitor.

A gastrointestinal endoscope is inserted through the mouth or anus. An ultrasound probe can be added to a gastrointestinal endoscope. This is called an endoscopic ultrasound. Depending on the area of interest, this device can also be passed through the mouth or anus.

Endoscopy is useful in early detection of ulcers and cancers in food pipe. It also helps in treating any obstruction in the intestinal and biliary tracts. Modern therapeutic endoscopy is of immense value in treating vomiting blood and bleeding from the rectum. Its other major advantage is the ability to perform biopsies (obtain small pieces of tissue) or cytology (obtain some cells with a fine brush) for microscopic examination to determine the nature of the abnormality and whether the abnormality is benign or malignant (cancerous).

Biopsies are taken for many reasons and may not mean that a cancer is suspected. Endoscopy also can be used to treat many conditions with its reach. The endoscope’s channels permit passage of accessory instruments enabling the examiner to treat many of the conditions such as stretching areas of narrowing (strictures), removal of benign growths such as polyps, accidentally swallowed objects, or treating upper gastrointestinal bleeding as seen in ulcers tears of the lining. These capabilities have markedly reduced the need of transfusion or surgery.