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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The irritable bowel syndrome (IBS) is a very common condition in gastroenterology clinics, but yet it is one of the pooly understood. A international working team in Rome, 1988, proposed that IBS is a functional intestinal disorder with chronic or recurrent gastrointestinal symptoms without structural or biochemical abnormalities. IBS was sub-classified into 3 groups; abdominal pain as the prominent feature with diarrhea, with constipation, with both while painless diarrhea and simple constipation without pain were excluded from IBS. There is a lot of data suggesting that IBS has a gut dysmotility, which is influenced by many stimuli (food, hormone, drug, menses, mechanical dilatation), including psychological stress. Moreover, currently available evidences implicate that IBS is a more generalized disorder of smooth muscle function not only in the intestine but also outside of the intestine.
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PMID:[Irritable bowel syndrome--criteria, sub-classification, etiology]. 128 43

It has been demonstrated that physical or psychological stress induces dysfunction of bowel movement and intestinal transit in rodents and human. There have been several reports concerning the psychiatric factors involved in the onset and clinical course of irritable bowel syndrome (IBS). We investigated patients with IBS who had been markedly disturbed in their daily life, and it was concluded that the most important psychiatric factor related to the onset and the clinical course of severely impaired IBS is a major depression, fulfilling the criteria of the DSM-III-R. Especially, in diarrhea predominant type of IBS, a major depression was considered to be strongly involved in the onset and the clinical course of IBS. Most of IBS patients with a major depression can be effectively treated with antidepressants and brief psychotherapy. Concerning treatment, the psychological background should be carefully considered.
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PMID:[The relation between irritable bowel syndrome and a major depression]. 128 47

Upper small bowel motility was recorded for more than 30 h in each of 22 patients with the irritable bowel syndrome (IBS) and in two control groups, one consisting of 10 healthy volunteers and the other of 5 patients with inflammatory bowel disease. When subjects underwent a long period of intermittent mental stress, one or more of three motor abnormalities occurred in 19 patients; and only one abnormality was seen in 1 control (p less than 0.0001). These abnormalities were the total abolition of migrating motor complexes under stress, and abnormal irregular contractile activity, which was either spontaneous or evoked by stress. Sometimes the irregular contractile activity coincided with the occurrence of typical IBS symptoms. Males predominated (p = 0.05) among those with spontaneous irregular motor activity, who tended to have more symptoms (p = 0.014) than did those affected only by stress. The data suggest that irritable bowel syndrome is a paroxysmal motor disorder which may be detected in the small bowel and which may be either spontaneous or evoked.
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PMID:The irritable bowel syndrome: a paroxysmal motor disorder. 286 4

The relationship between abdominal pain and bowel gas from bacterial fermentation of undigested carbohydrate was investigated in nine patients with irritable bowel syndrome (IBS), six lactose malabsorbers, and 11 asymptomatic controls. All subjects took breath samples and marked analog scales for abdominal pain, bloating, and psychological stress hourly during all waking hours for 7 days. Breath samples were analyzed for hydrogen concentration within 3 days, and the concentration was corrected for storage time. Symptoms of pain and bloating were significantly more common in IBS patients than in lactose malabsorbers or normal controls, and pain was significantly correlated with bloating in IBS patients. Breath hydrogen concentration was similar in all three groups, and breath hydrogen was not correlated with pain ratings in IBS patients. Thus, abdominal pain may be related to bloating from gastrointestinal gas, but bacterial fermentation cannot be the cause of such gas. The most likely source is swallowed air. This study also demonstrates the feasibility of monitoring hydrogen production in the bowel in field studies by having subjects collect hourly breath samples.
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PMID:Intestinal gas production from bacterial fermentation of undigested carbohydrate in irritable bowel syndrome. 292 57

The article presents some individual perceptions of the nature of the disease we call the Irritable Bowel Syndrome (IBS), and attempts to rationalise the variable presenting features, the influence of the psyche and the lack of pathological or biochemical markers. Among the topics discussed include the existence of recognisable subsets of the disease, the influence of mental stress, and the pathophysiology of the presenting symptoms. My impression is that IBS is a condition, in which the gut is hypersensitive and hyper-reactive to mechanical and chemical stimuli and as such, can be compared with asthma in the respiratory system. This hyper-reactivity could be caused by increased mucosal permeability, increased numbers and/or responses of effector cells such as mast cells or enterochromaffin cells, and enhancement of intrinsic nerve reflexes by increased activity of efferent vagal fibres.
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PMID:Irritable bowel syndrome (IBS)--definition and pathophysiology. 347 18

Effects of an artificial mental stress on colonic motility, autonomic nervous system, and gastrointestinal hormones were examined in patients with irritable bowel syndrome (IBS). The subjects were 20 patients with typical IBS and 12 controls. A transducer was inserted to the sigmoid colon from the anus for measuring colonic intraluminal pressure, and mirror drawing test was loaded as psychological stress. At the same time, coefficient of variation of R-R interval on ECG (CV-RR) was measured and the levels of plasma catecholamines, gastrin, glucagon, and motilin were assessed. Colonic motility showed a significant increase in the IBS patients during the stress compared with that in controls (p less than 0.01). Motilin also increased significantly in the IBS patients after the stress (p less than 0.01). CV-RR and motilin revealed positive relationship with colonic motility alteration in the IBS patients although no significant change was detected in controls. These phenomena are thought to be due to autonomic nervous dysfunction and/or gastrointestinal hormonal derrangments induced by psychological stress. It is suggested that organ specificity of the alimentary tract for the stress exists in this disease.
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PMID:Colonic motility, autonomic function, and gastrointestinal hormones under psychological stress on irritable bowel syndrome. 361 51

About five per cent of the adult population each year will see their doctor with complaints that are finally characterised as irritable bowel syndrome (IBS). The complaints are constipation (perhaps alternating with diarrhoea), abdominal pain (dull or colicky), abdominal distension, abdominal rumbling and flatulence. The diagnosis of IBS implies that a relevant examination has precluded any organic disease. The etiology is unknown and the syndrome probably does not represent a disease entity. It is therefore difficult, if not impossible, to produce a definite rationale of treatment. However, several aspects of the pathogenesis of the individual symptoms of IBS are well known: 1) chronic constipation is most likely due to fibre-depleted diet, psychological factors, local organic disorders (e.g., anal fissures, hemorrhoids, diverticulosis) and disturbance of the body fluid balance (e.g., high consumption of diuretic compounds such as coffee and tea); 2) pain is related to spasms and motility disturbances causing increased intraluminal pressure; 3) meteorism is not due to an increased amount of intestinal gas, but "air traps" and segmental accumulation of gas seem to occur. Furthermore, psychopathological factors and perhaps also food intolerance may play an etiological role. At present the rationale of treatment in IBS is: 1) management of constipation, 2) ease of spasms, 3) reduction of surface tension of intestinal contents, 4) ease of mental stress.
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PMID:Irritable bowel syndrome: current concepts and future trends. 389 85

To investigate the influence of the brain-gut interactions on the pathophysiology of irritable bowel syndrome (IBS), we compared such patients (n = 10) with healthy control subjects (n = 11) by measuring the pressure of the colon and small intestine simultaneously with analysis of power spectrum of the electroencephalography (EEG) under mental stress and administration of neostigmine. Stress slightly increased the colonic motility index, reduced the percentage of alpha power, and increased the percentage of beta and theta power of the EEG in the patients with IBS more than in the controls (p < 0.05). The patients with IBS had a longer phase II (p < 0.01) and shorter phase I (p < 0.02) of fasting duodenal motor activity than the controls. Neostigmine (10 micrograms/kg) caused a significant difference in the colonic motility index (p < 0.01) and power spectra of EEG (p < 0.05) in the patients with IBS compared to the controls. Significant positive correlation was detected between colonic motility and power spectral change induced by stress (r = 0.46, p < 0.05) or neostigmine (r = 0.51, p < 0.01). These results suggest that patients with IBS have exaggerated responsivity of the gut and the brain to mental stress and cholinergic stimulation. Moreover, there is a possibility that these exaggerated responses are related.
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PMID:Brain-gut response to stress and cholinergic stimulation in irritable bowel syndrome. A preliminary study. 818 28

Communications along the brain-gut axis involve neural pathways as well as immune and endocrine mechanisms. The two branches of the autonomic nervous system are integrated anatomically and functionally with visceral sensory pathways, and are responsible for the homeostatic regulation of gut function. The autonomic nervous system is also a major mediator of the visceral response to central influences such as psychological stress. As defined, functional disorders comprise a constellation of symptoms, some of which suggest the presence of altered perception, while other symptoms point to disordered gastrointestinal function as the cause of the symptoms. A growing number of reports have demonstrated disordered autonomic function in subgroups of functional bowel patients. While a number of different methods were used to assess autonomic function, the reports point to a generally decreased vagal (parasympathetic) outflow or increased sympathetic activity in conditions usually associated with slow or decreased gastrointestinal motility, while other studies found either an increased cholinergic activity or a decreased sympathetic activity in patients with symptoms compatible with an increased motor activity. Under certain conditions, altered autonomic balance (including low vagal tone and increased sympathetic activity) may alter visceral perception. Autonomic dysfunction may also represent the physiological pathway accounting for many of the extraintestinal symptoms seen in irritable bowel syndrome patients and some of the frequent gastrointestinal complaints reported by patients with disorders such as chronic fatigue and fibromyalgia.
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PMID:The autonomic nervous system in functional bowel disorders. 1020 3

Although there is a wide variability in symptoms, disorders of colonic motility are the most prominent features in irritable bowel syndrome (IBS). Stool weight is within the normal range but many patients appear to have abnormal rectal sensations. Straining even with soft stool is common. Dietary fibre stimulates ileocolonic flow and may induce more symptoms in IBS than normal. There is evidence of increased responsiveness of the IBS colon, both to the effect of eating and to stress. Defaecatory disorders are common and may reflect both increased or decreased rectal sensitivity. The normal colon is quiescent during sleep, but in IBS coma sleep is often abnormal, with more periods of arousal and the colon consequently more active. There is evidence of increased responsiveness to corticotrophin releasing factor, which mediates much of the effect of stress on the gut. Many patients show a sympathetic/vagal imbalance with relative excess of sympathetic influence in keeping with increased levels of psychological stress and anxiety. There is undoubtedly more than one cause of IBS and around 25% appear to develop symptoms after an infectious enteritis. This has effects on the entero-endocrine system which may take many years to subside.
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PMID:Disturbances in large bowel motility. 1058 Sep 17


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