# Visceral Hypersensitivity and IBS



## eric (Jul 8, 1999)

This might give some clues to some peoples intiating event up to IBS.A New Model of Chronic Visceral Hypersensitivity in Adult Rats Induced by Colon Irritation During Postnatal Development. Al-Chaer ED, Kawasaki M, Pasricha PJ Division of Gastroenterology, Departments of Internal Medicine and Anatomy and Neurosciences, University of Texas Medical Branch, Galveston, Texas. [Record supplied by publisher] Background & Aims: The irritable bowel syndrome (IBS) is a common disorder characterized by abdominal pain in the setting of altered perception of viscerosensory stimuli. This so-called visceral hyperalgesia occurs in the absence of detectable organic disease in the peripheral organs and may cause normal or physiologic contractions to be perceived as painful. Although the pathogenesis of IBS remains speculative and is probably multifactorial, a prevailing paradigm is that transient noxious events lead to long-lasting sensitization of the neural pain circuit, despite complete resolution of the initiating event. Methods: Neonatal male Sprague-Dawley rats received either mechanical or chemical colonic irritation between postnatal days 8 and 21 and were tested when they became adults. The abdominal withdrawal reflex and the responses of viscerosensitive neurons were recorded during colon distention. Results: Colon irritation in neonates, but not in adults, results in chronic visceral hypersensitivity, with characteristics of allodynia and hyperalgesia, associated with central neuronal sensitization in the absence of identifiable peripheral pathology. Conclusions: These results concur largely with observations in patients with IBS, providing a new animal model to study IBS and validating a neurogenic component of functional abdominal pain that encourages novel approaches to health care and research. PMID: 11054385 ------------------ http://www.ibshealth.com/ www.ibsaudioprogram.com


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## JeanG (Oct 20, 1999)

Very interesting, Eric. So this is referring to colonic irritation when very young affecting rats as adults?Thanks for posting this.







JeanG


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## Mike NoLomotil (Jun 6, 2000)

Yeah, it has been found in human studies as well that there is a population of IBS-symptom-set patients whose IBS onset follows either an inflammatory event (pathogenic or "toxic") which has primarily resolved, but a residual chronic reactivity remains. Also there are assciations established with the use of non-steroidal anti-inlfammatories for extended periods...again creating a chronic reactivity. These are consistent with the in vitro examination granulocytic, lymphocytic, and even platelet hypersensitivity reactions in IBS (and certain other symptom-sets): loss of cell wall stability and active release of multiple immune-mediators in the presence of benign substances that are now seen as "non-self" and reacted to, producing a chronic state of low-level immunologic reaction punctuated with episodes of increased severity. They are in varying degrees vasocative, neuroactive, and also can lead to synthesized mediator production.MNL________________ www.leapallergy.com


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