The oesophagus is the tube that carries the food down to the stomach. It is also called the gullet. The stomach is a muscular pouch lying between the oesophagus and the first part of the bowel, called the duodenum.
The lining of the upper part of the stomach produces acid and a digestive chemical, called pepsin. Together with the action of the stomach muscle, these chemicals break down food and drink to produce a fine paste. The cells lining the lower part of the stomach control how much acid and pepsin is made in the upper part of the stomach.
A ring of muscle at the outlet of the stomach, called the pylorus or pyloric sphincter, relaxes from time to time, to let the food paste through into the duodenum.
What is a gastroscopy?
Strictly speaking, a gastroscopy is a visual examination of your stomach, as gastro means stomach. However, on the way, we examine the back of your mouth and your oesophagus. We can also examine beyond your stomach into the upper part of the small bowel, called the duodenum.
The examination is done through the mouth using a flexible telescope, called an endoscope, which is about as thick as a pencil. The endoscope lets the doctor see the inside of the gastrointestinal tract and any problems.
The examination is also called an upper gastrointestinal endoscopy, as it examines the upper gastrointestinal tract. You may also hear it called an upper GI endoscopy.