This chapter emphasises the importance of psychological processes in influencing the gastrointestinal tract. Chronic functional gastrointestinal symptoms can be seen as a result of dysregulation of intestinal motor, sensory, and central nervous system (CNS) activity.

A central aspect of functional gastrointestinal disorders is pain, and anxiety is seen as an important modulating factor in pain perception. Perception of somatic stimuli probably differs between patients and in some patients there is an exaggerated experience of pain in response to mildly painful or even normal visceral stimuli. Sensitisation can lead to somatisation, which means the development of somatic complaints which cannot be fully explained by any known medical …