Anurag Agrawal, PhD, MRCP
Clinical Research Fellow
Neurogastroenterology Unit
University of Manchester
South Manchester, UK
Dr. Agrawal has had a particular interest is in Irritable Bowel Syndrome and related conditions and he has been involved with physiological and clinical research as part of his PhD. He is part of the South Manchester Functional Bowel Service which is devoted to looking after these patients as well as undertaking research into these illnesses. He has co-authored several original publications, reviews and book chapters, and has presented at major national and international conferences.
Bloating and distention in irritable bowel syndrome: The role of visceral sensation
Agrawal A, Houghton LA, Lea R, Morris J, Reilly B, Whorwell PJ.
Gastroenterology 2008;134:1882-1889.
ABSTRACT
Background & Aims: Abdominal bloating is an extremely intrusive symptom of irritable bowel syndrome (IBS) that is not always accompanied by an increase in abdominal girth (distention), raising the possibility that these 2 features of the condition may not share a common pathophysiology. A number of mechanisms have been postulated for bloating and distention, but the role of visceral sensation, which is often abnormal in IBS, has not been previously investigated, and this study aimed to address this question.
Methods: Abdominal girth measured by ambulatory abdominal inductance plethysmography and bloating severity was recorded over 24 hours in 39 IBS-constipation (ages, 18-73 years) and 29 IBS-diarrhea patients (ages, 20-59 years) meeting Rome II criteria. Within 1 week, rectal sensory thresholds were assessed with a barostat using the ascending method of limits and tracking.
Results: IBS patients who suffered with bloating alone had lower thresholds for pain (P = .005), desire to defecate (P = .044), and first sensation (P = .07) compared with those who had concomitant distention irrespective of bowel habit. When patients were grouped according to sensory threshold, hyposensitive individuals had distention significantly more than those with hypersensitivity (P = .001), and this was observed more in the constipation subgroup. Static and dynamic compliance did not differ among any of the groups.
Conclusions: Elevated colonic lumenal serine-protease activity of IBS-D patients evokes a PAR-2 mediated colonic epithelial barrier dysfunction and subsequent allodynia in mice, suggesting a novel organic background in the pathogenesis of IBS.