Investigation of the brain–gut axis

Abstract Advances in brain–gut investigation techniques have been influential in the progress, and vastly improved understanding of functional gastrointestinal disorders in the Rome IV era. In this chapter, we consider the development of technologies including non-invasive brain stimulation, cortical evoked potentials, models of pain processing, functional brain imaging and vagal tone measurement. We summarize the key findings to date from studies using these techniques and their role in our current understanding and future utility in functional gastrointestinal and motility disorders.