Intestinal and extraintestinal symptoms in functional gastrointestinal disorders.

Functional gastrointestinal disorders such as irritable bowel syndrome or functional dyspepsia have traditionally been regarded as syndromes limited to the digestive system. However, both clinical experience and published evidence show that patients with such disorders also report a series of other symptoms of physical distress, such as fibromyalgia and irritable bladder and alterations in vital functions, such as sleep, libido, appetite and energy level. Some of these extraintestinal symptoms can be explained in the context of an evolving comprehensive disease model which views functional gastrointestinal disorders as manifestations of alterations in the interactions between the nervous system, the viscera and the musculoskeletal system. Alterations in central circuits concerned with arousal, attention and fear, cognitions about bodily symptoms and possible alterations in the hypothalamic pituitary adrenal (HPA) axis may all contribute to the wide range of symptoms reported by affected patients.