Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Functional bowel disorders are characterized by the presence of a visceral hyperalgesia in most patients. This visceral hyperalgesia is related to an enhanced perception of sensations originating from the gut. Stressful events can dramatically influence the course of functional bowel disorders, and patients suffering from these syndromes appear to be more susceptible to the stressful events of daily life. However, until now, few studies have evaluated the relationship between stress and visceral perception. Some studies of healthy volunteers indicated contradictory results, but the studies used different methodologies. During stress conditions, either physical or mental, thresholds of perception of rectal distension were increased, suggesting a 'distraction effect', or were decreased, supporting a sensitizing effect of stress. In most studies, rectal compliance was not affected, but stress has been shown to alter the rectal tone, as measured by a barostat. One study comparing irritable bowel syndrome patients with controls demonstrated the importance of cognitive processes in the modulation of visceral perception by stress. Animal studies have also demonstrated the sensitizing effect of stress on the perception of rectal distension. Mediators involved may be numerous, but corticotropin-releasing factor has been demonstrated to play a major role at the central level. Mast cells and histamine release may play a role at the peripheral level. Stress can thus be included in an integrative model explaining the pathophysiology of functional bowel disorders. Advances in the understanding of the relationship between stress and visceral perception may constitute a basis for a therapeutic approach of functional bowel disorders targeted on the central nervous system.
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PMID:Stress and visceral perception. 1020 6

A better understanding of the cortical processes underlying attentional modulation of visceral and somatic pain in health are essential for interpretation of future imaging studies of hypervigilance towards bodily sensations which is considered to be an aetiologically important factor in the heightened pain reported by patients with irritable bowel syndrome and fibromyalgia. Twelve healthy subjects were recruited for this study. Simultaneous trains of electrical pulses (delivered to either the rectum or lower abdomen) and auditory tones lasting 6 s were delivered to the subjects during a whole-brain functional scan acquisition. Subjects were instructed to attend to the auditory tones (distracter task) or electrical pulses (pain task). Pain intensity ratings were significantly lower during the distraction task compared with the pain task (P < 0.01) in both sensory modalities. The left primary somatosensory cortex increased in activity with increasing pain report, during attention to visceral pain. Bilateral anterior insula (aIns) cortex activity increased with increasing somatic pain report independent of the direction of attention. Conversely, the primary and secondary auditory cortices significantly increased in activation with decreased pain report. These results suggest that pain intensity perception during attentional modulation is reflected in the primary somatosensory cortex (visceral pain) and aIns cortex activity (somatic pain).
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PMID:Attentional modulation of visceral and somatic pain. 1759 38

Two possible roles of selective attention in the development and maintenance of functional gastrointestinal disorders (FGID) such as irritable bowel syndrome (IBS) were examined. First, hypervigilance to pain within FGID may exacerbate pain perception and pain-related distress. Second, hypervigilance to socially threatening stimuli could account for the disrupted social functioning reported by patients. Furthermore, stress-related variations in reported symptom severity and functioning impairments may reflect changes in cognitive bias with psychological state. Patterns of selective attention were probed within a sample of putative FGID participants (pFGID). The effect of rumination induction on performance on a modified exogenous cueing task was examined. Thirty-three women with pFGID and 27 matched controls responded to dot probes following pain, social threat and neutral word cues, both before and after rumination (passive self-focused thought), or distraction induction. Reaction times revealed that after rumination but not neutral distraction, pFGID participants showed enhanced attention to social threat words, but not to pain or neutral words. Between-group differences in mood, anxiety or depression could not account for these effects. These results implicate selective attention in social but not pain-related idiosyncrasies in FGID including IBS.
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PMID:Cognitive processing in putative functional gastrointestinal disorder: rumination yields orientation to social threat not pain. 1947 56

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder associated with chronic abdominal pain and altered pain processing. The aim of this study was to examine whether attentional processes contribute to altered pain inhibition processes in patients with IBS. Nine female patients with IBS and nine age-/sex-matched controls were included in a pain inhibition paradigm using counter-stimulation and distraction with electroencephalography. Patients with IBS showed no inhibition of pain-related brain activity by heterotopic noxious counter-stimulation (HNCS) or selective attention. In the control group, HNCS and selective attention decreased the N100, P260 and high-gamma oscillation power. In addition, pain-related high-gamma power in sensorimotor, anterior cingulate and left dorsolateral prefrontal cortex was decreased by HNCS and selective attention in the control group, but not in patients with IBS. These results indicate that the central pain inhibition deficit in IBS reflects interactions between several brain processes related to pain and attention.
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PMID:Electrophysiological investigation of the contribution of attention to altered pain inhibition processes in patients with irritable bowel syndrome. 3302 74