Gastroscopy is a technique by which a doctor can look inside the oesophagus, stomach and small intestine to detect a peptic ulcer, reflux or tumour. The term gastroduodenoscopy may be used when the instrument is passed as far as the duodenum.
A gastroscope is an instrument about one metre long, consisting of a highly flexible thin tube. There is a light at the end that is inserted and a control box at the end remaining outside. The doctor can manipulate the tube on its way down and see everything that is present. Long flexible forceps can pass down the tube and take a sample of tissue from inside the intestine.
The patient will have to fast overnight and then go to hospital or day surgery centre for a few hours.
The patient is sedated to prevent gagging and the gastroscope is passed through the mouth and throat and into the stomach. The procedure is not painful or uncomfortable. The doctor will turn on the light in the endoscope and darken the room to maximise the degree of illumination. The patient will be asked to lie in different positions to bring areas into view and will comply normally, but because of the sedation they will usually have no memory of these instructions or the procedure itself. When the investigation is complete, the doctor will slowly withdraw the instrument. The whole procedure takes about ten minutes.
The patient is allowed to go home when the sedation wears off but must not drive and should arrange for someone to escort them as they may still be drowsy.