The long tube that makes up the gastrointestinal tract is composed of a variety of tissue types and is the largest internal organ of the body. Its main function is to digest food and absorb the released nutrients. Furthermore, it is subdivided into functionally distinct regions that each mediate one of a variety of actions upon the food consumed, including ingestion, propulsion, secretion, digestion, absorption and expulsion. Autonomic neuronal circuitry is intimately involved in controlling many of these multiple functions of the gut, making it an appealing subject for the study of neuroscientists. This book reviews the state of current knowledge on the innervation of the gut by the enteric nervous system, and its interface with the extrinsic innervation, from a number of different perspectives, with the aim of providing a comprehensive and accessible account of the subject.