An exaggerated sensory component of the gastrocolonic response in patients with irritable bowel syndrome

Abstract

Background/aims-Visceral hypersensitivity is a feature of the irritable bowel syndrome (IBS). Postprandial symptoms are common in these patients. The eVects of nutrients on colonic perception in IBS are incompletely understood. Subjects-We studied 13 healthy subjects and 16 patients with IBS-eight had diarrhoea predominant (IBS-D) and eight constipation predominant (IBS-C) IBS. Methods-Colonic perception thresholds to balloon distension and viscerosomatic referral pattern were assessed before and after duodenal infusion of lipid or saline, respectively. At the end of the infusions, plasma levels of gastrointestinal peptides were determined. Results-Lipids lowered the thresholds for first sensation, gas, discomfort, and pain in the IBS group but only for gas in the control group. The percent reduction in thresholds for gas and pain after lipids was greater in the IBS and IBS-D groups but not in the IBS-C group compared with controls. IBS patients had an increased area of referred discomfort and pain after lipids compared with before infusion whereas the referral area remained unchanged in controls. No group diVerences in colonic tone or compliance were observed. In both groups higher levels of cholecystokinin, pancreatic polypeptide, peptide YY, vasoactive intestinal polypeptide, and neuropeptide Y were seen after lipids. Motilin levels were higher in patients and diVerences in the subgroups were observed. Levels of corticotrophin releasing factor were lower in the constipated group than in the diarrhoea group. Conclusions-Postprandial symptoms in IBS patients may be explained in part by a nutrient dependent exaggerated sensory component of the gastrocolonic response.

Perceived food intolerance in subjects with irritable bowel syndrome – etiology, prevalence and consequences

“…Psychological factors not measured in this study, such as attribution, might be involved in the pathogenesis. The established changes in visceral sensory, perceptual and neuroendocrine responses seen in these subjects has been related to low-grade mucosal inflammation, IgG antibodies and other aspects of food allergy, infections, changes in the microflora, etc (Simren et al, 2001a;Barbara et al, 2002;Isolauri et al, 2004;Posserud et al, 2004). All these aspects of perceived food intolerance deserve further investigations.…”

The Alleviating Pain Effect of Aqueous Extract from Tong-Xie-Yao-Fang, on Experimental Visceral Hypersensitivity and Its Mechanism

“…Coates et al 26) confirmed that the 5-HT levels in the rectal mucosa in patients with IBS were significantly decreased compared with the control group. Simren et al 27) showed that 5-HT levels in the plasma of IBS-D patients were significantly lower than in healthy volunteers.…”

Effects of electroacupuncture on corticotropin-releasing hormone in rats with chronic visceral hypersensitivity

“…However, the [18] . IBS patients show a significantly reduced tolerance of balloon dilatation in the colon and rectum, displaying increased pain intensity [19] . Some scholars believe that this sensitivity may be related to an enhanced sensation in the peripheral or central nervous system, and it may also be related to abnormalities in the processing and integration of the incoming signal in the brain [20] .…”