Gastroscopy (upper endoscopy) is a procedure that uses a flexible endoscope to see inside the upper digestive tract - including the oesophagus, stomach and the first part of the small intestine.
During an upper endoscopy a thin flexible tube is carefully fed down the oesophagus into the stomach and the small intestine. A small camera on the endoscope transmits an image to a monitor, allowing close examination of the intestinal lining.
It is used to determine the cause of abdominal pain, nausea, vomiting, swallowing difficulties, gastrix reflux, unexplained weight loss, anaemia or bleeding in the upper digestive tract.
Upper endoscopy is also used to remove stuck objects (including food), treat conditions such as bleeding ulcers and biopsy tissue. During a biopsy, a small piece of tissue is removed for later examination with a microscope.