Expert Commentary -- Bloating, Distension, and the Irritable Bowel Syndrome

Richard Lea, MD; Peter J. Whorwell, MD

In This Article

The Epidemiology of Bloating

The symptom of bloating is extremely common and has been experienced by most people at some stage in their lives. Indeed, one recent population survey reported that 16% of apparently healthy individuals experience bloating at least once a month,[1] and bloating within the previous 3 months was reported by 30% of respondents in the US Householders' survey.[2] Despite not being a requirement of the current Rome II diagnostic criteria,[3] bloating is even more prevalent in patients with irritable bowel syndrome (IBS), with at least 75% of patients reporting bloating as part of their symptom complex.[4] Patients with IBS typically suffer from bloating 25% of the time compared with pain 33% of the time.[5] Furthermore, nearly two thirds of patients seen in tertiary care centers rate bloating as their most severe symptom, compared with approximately one third who feel that pain is their worst symptom.[6] Bloating does not appear to be age-related,[2,7,8] although it is more prevalent in women than in men[1,9,10,11] and this may be because men sometimes refer to it as a "tight sensation" in the abdomen. Typically, bloating tends to become worse as the day progresses and after ingestion of food,[4,12] and is sometimes relieved by the passage of stool or flatus.[4]

Some studies show that patients with IBS with predominant constipation experience more bloating,[13] with up to 90% of constipated IBS patients reporting the symptom.[14] However, other studies report that bloating is equally common in patients with IBS with diarrhea.[15,16] Approximately 40% of female IBS patients report that bloating is related to their menstrual cycle, usually being exacerbated perimenstrually[4,12,17]; however, bloating is not limited purely to the perimenstrual time of the cycle.

Although abdominal distension formed part of the original diagnostic criteria for IBS described by Manning and colleagues,[18] later studies have suggested that bloating/distension is not a reliable indicator of the disease, especially in men,[9,11] and this was confirmed in factor analyses leading to the development of the current Rome criteria.[11,19,20]


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