The sensation of bloating is often ranked as the most bothersome symptom by patients with irritable bowel syndrome (IBS).
The relationship between abdominal bloating and actual distention manifest as an increase in abdominal girth is controversial.
Investigation of this problem has been hampered by the lack of a reliable ambulatory technique to measure abdominal girth.
Dr Houghton and colleagues from England compared diurnal variation in girth in IBS, relating these changes to the sensation of bloating.
The research team used the technique of abdominal inductance plethysmography in 50 patients and 20 healthy volunteers.
|48% showed distention beyond the 90% control range|
The team recorded abdominal girth for 24 hours in 20 female patients with IBS and constipation, aged 18 to 73 years.
The researchers also assessed 20 female patients with IBS and diarrhea, aged 25 to 62 years.
A further 10 female patients with alternating IBS, aged 21 to 59 years and meeting Rome II criteria were evaluated.
These groups were compared to 20 healthy female controls, aged 18 to 67 years.
All subjects pursued normal daily activities, recording their symptoms of bloating and pain together with bowel habit.
The researchers found that all patients with IBS, irrespective of bowel habit, reported significantly greater bloating than controls.
The team noted that 48% of patients also showed distention beyond the 90% control range, with this being most prominent in IBS with constipation.
Bloating correlated strongly only with distention in IBS with constipation.
The team found that neither bloating nor distention in IBS was related to body mass index, age, parity, or psychologic status.
Dr Houghton's team concludes, “Abdominal distention is a clearly definable phenomenon in IBS that can reach 12 cm.”
“However, it only occurs in half of patients reporting bloating, and the 2 only correlate in IBS with constipation.”
“Bloating and tentiodisn may differ pathophysiologically and this appears to be reflected in the bowel habit subtype.”