Gastroscopy is a procedure where a thin flexible tube (endoscope, gastroscope) is used to examine the upper digestive tract.
The tube is inserted into the mouth and travels down the food pipe (oesophagus), then into the stomach and first part of the small intestine (duodenum), to view these areas.
The endoscope contains a light and video camera that transmits images to a monitor, where they can be seen by a doctor.
Gastroscopy is usually done to investigate symptoms such as indigestion, nausea, or difficulty swallowing. It can show if there is inflammation, an ulcer, a polyp or a cancer. It can also be used to diagnose digestive disorders such as coeliac disease or lactose intolerance.
Sometimes gastroscopy is performed to treat conditions, such as bleeding ulcers, or to widen a narrow oesophagus (known as dilatation), or to remove a foreign body or polyps. Diagnostic biopsies can also be taken during the procedure.