Abdominal bloating and distension: is it a motility or visceral hypersensitivity problem?

Fernando Azpiroz, Digistive System Rearch Unit, University Hospital Vall d'Hebron; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas; Department of Medicine, Universidad Autónoma de Barcelona, Barcelona,Spain

ABSTRACT

Abdominal bloating and distension are frequently attributed to intestinal gas, but the

mechanism by which gas might produce the symptoms is not clear. In most cases, the rate

of gas production, as well as the volume of intestinal gas, is within the normal range.

Furthermore, detailed studies measuring the volume of non-gaseous intestinal content

have not detected consistent differences related to abdominal bloating and distension. In

this context, bloating may be related to gut hypersensitivity. On the other hand, visible

abdominal distension seems a behavioral response, featuring a diaphragmatic contraction

and descent with anterior wall protrusion. Indeed, abdominal distension can be corrected

by abdomino-phrenic electromyography-guided biofeedback. However, why these patients

acquire this abnormal behavior remains unknown. Likewise, the factors that trigger the

episodes of abdominal distension have not been identified, but conceivably, the perception

of bloating sensation may play a role (Table 1). Proper pathophysiological diagnosis seems

important for the management of these patients.

Keywords: Key words: Abdominal distension. Abdominal bloating. Intestinal gas. Viscerosomatic responses.