Increased colonic pain sensitivity in irritable bowel syndrome is the result of an increased tendency to report pain rather than increased neurosensory sensitivity

Abstract

Objective: The aim was to determine whether lower visceral pain thresholds in irritable bowel syndrome (IBS) primarily reflect physiological or psychological factors. Methods: Firstly, 121 IBS patients and 28 controls underwent balloon distensions in the descending colon using the ascending methods of limits (AML) to assess pain and urge thresholds. Secondly, sensory decision theory analysis was used to separate physiological from psychological components of perception: neurosensory sensitivity (p(A)) was measured by the ability to discriminate between 30 mm Hg vs 34 mm Hg distensions; psychological influences were measured by the report criterion-that is, the overall tendency to report pain, indexed by the median intensity rating for all distensions, independent of intensity. Psychological symptoms were assessed using the Brief Symptom Inventory (BSI). Results: IBS patients had lower AML pain thresholds (median: 28 mm Hg vs 40 mm Hg; p,0.001), but similar neurosensory sensitivity (median p(A): 0.5 vs 0.5; p = 0.69; 42.6% vs 42.9% were able to discriminate between the stimuli better than chance) and a greater tendency to report pain (median report criterion: 4.0 (''mild'' pain) vs 5.2 (''weak'' pain); p = 0.003). AML pain thresholds were not correlated with neurosensory sensitivity (r = 20.13; p = 0.14), but were strongly correlated with report criterion (r = 0.67; p,0.0001). Report criterion was inversely correlated with BSI somatisation (r = 20.26; p = 0.001) and BSI global score (r = 20.18; p = 0.035). Similar results were seen for the non-painful sensation of urgency. Conclusion: Increased colonic sensitivity in IBS is strongly influenced by a psychological tendency to report pain and urge rather than increased neurosensory sensitivity.

Gastrointestinal symptoms and psychological well-being in patients with microscopic colitis

“…As our patients were recruited from hospitals and not from the primary health care, we can suspect them to have a more severe disease (1). Thus, the histological picture may be of minor importance in IBS compared to cognitive and psychosocial functions (21), explaining the impaired psychological well-being and more pronounced symptoms in our IBS patients, although similar histopathology. The discussion above is provided that idiopathic IBS is the same as IBS associated with MC and IBD.…”

“…However, the increased colonic sensitivity in idiopathic IBS is more influenced by a psychological tendency to report pain than neurosensory sensitivity (21). Irritable bowel syndrome does have a peripheral component, but the central components become more prominent as disease severity increases (22).…”

Visceral and somatic hypersensitivity, autonomic cardiovascular dysfunction and low-grade inflammation in a subset of irritable bowel syndrome patients

“…Compared with "rapid phasic distension", which mainly stimulates the intestinal serosa receptors, the main effect of AML is through the stimulation of the intestinal mucosa and submucosa receptors. These receptors are involved in different nerve conduction pathways while also participating in intestinal perception (Mertz et al, 1995;Dorn et al, 2007). Visceral hypersensitivity is a biological marker in some IBS cases, especially D-IBS patients.…”

Increased Postprandial Colonic Motility and Autonomic Nervous System Activity in Patients With Irritable Bowel Syndrome: A Prospective Study

“…Subjects and study design have been previously reported, 19,20 but the hypothesis that there are age-related differences in ANS activity and its response to meals and intraluminal distention has not been described previously. 19,20 Subjects were recruited via advertisements or physician referrals and screened by telephone. The study population consisted of 156 patients who fulfilled the Rome III criteria for IBS, had received a physician diagnosis of IBS, and had current symptoms (abdominal pain or discomfort at least 3 days per month in the last 3 months).…”