The investigation of the oesophagus has seen major advanciens thes econd half of the 20th Century as technology has developed and our understanding of the physiology and pathophysiology of oesophageal diseases has increased. In thew ake of these changes, research and development of oesophageal function tests have lead to a newbr eed of specialists in medicine to provide for the needs of the clinician in diagnosis and management of patients with oesophageal diseases.