Oesophagus. Coloured X-ray of a barium meal being swallowed by a healthy human oesophagus (gullet). The image on the left was taken before the one on the right. The front of the body is at right. The oesophagus is the central tube (blue/white) that is seen to the right of the spinal vertebrae (also blue/white). Ribs are also seen, running from left to right, and the diaphragm and upper abdomen are the white mass in the lower frame. The oesophagus is the first part of the digestive tract, taking food and drink from the mouth to the stomach. The barium in the meal (white, in the oesophagus) is opaque to X-rays, allowing the diagnosis of oesophagal disorders.