Book excerpt: "Prior to the development of the first fibre-optic endoscopes in the 1960's, gastroenterology, in common with other traditional medical specialties, relied on biochemical and radiological techniques in order to investigate the gastrointestinal tract. Histological confirmation of a disease process usually required the presence of a surgeon, was invasive, and carried inherent risks. Because of a rapid improvement in technology, we are now able to sample the entire gastrointestinal tract from the mouth and anus through to the ileal / jejunal junction"--