Fibre optic gastroscopes consisted of a tube composed of thousands of small fibres which allow light to be reflected around corners. This meant the tube could bend as it was inserted into the body. Fibre optic gastroscopes were developed in the 1960s and the technology let doctors view the lining of the stomach and intestines. The procedure is called a gastroscopy and it had been attempted since the 1800s. However, it remained uncommon until the technical advances of the twentieth century.

The operation can be done on a conscious patient. The physician looks down the tube, takes photographs, and uses long, thin forceps to take a small biopsy. This is tested in the laboratory. The PFS-F III fibre optic gastroscope was made in Japan by British company Specfield Limited.