Various functional gastrointestinal pain syndromes have been defined, but there is substantial overlap between them. There is also substantial overlap with other functional disorders such as chronic fatigue syndrome, fibromyalgia, and chronic pelvic pain. The classification system for functional gastrointestinal disorders (FGID) therefore remains controversial and is seldom used outside specialist and research settings. Furthermore, the psychological management of these different syndromes is essentially similar.

In primary care about half of the patients seen with gut complaints have FGID, the most common disorder being irritable bowel syndrome. A UK general practitioner is estimated to see eight patients with irritable bowel syndrome every week, one of whom will be presenting for the first time.

The quality of life of patients with chronic FGID is far poorer than in the general population, and is even significantly lower than in patients with many other chronic illnesses. These patients are not merely the “worried well.” It is also important to resist the temptation to think of FGID as exclusively psychological disorders. A biopsychosocial approach is preferable. Physiological studies have suggested that patients with FGID have abnormal visceral sensation and abnormal patterns of bowel motility. Both psychological and physiological factors are involved, with the relative contribution of these varying among patients.

Aetiological factors include physiological and psychological predisposition, early life experience, and current social stresses. It has been shown that a combination of psychological factors and sensitisation of the gut after infection can trigger irritable bowel syndrome in adults.

Emotional distress—The degree …