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

Stress is known to affect symptoms of irritable bowel syndrome (IBS) probably by an alteration of visceral sensitivity. We studied the impact of maximal tolerable rectal distensions on cortisol levels in patients with IBS, chronic constipation and controls, and evaluated the effect of the experimental situation per se. In twenty-four IBS patients, eight patients with chronic constipation and 15 controls salivary cortisol was measured before and after repetitive maximal tolerable rectal balloon distensions and at similar times in their usual environment. Rectal sensitivity thresholds were determined. IBS patients but not controls and constipation patients had higher cortisol levels both before and after the experiment compared with similar times on an ordinary day in their usual environment (P = 0.0034 and 0.0002). There was no difference in salivary cortisol level before compared with after rectal distensions. The IBS patients had significantly lower thresholds for first sensation, urge and maximal tolerable distension than controls (P = 0.0247, 0.0001 and <0.0001) and for urge and maximal tolerable distension than patients with constipation (P = 0.006 and 0.013). IBS patients may be more sensitive to expectancy stress than controls and patients with constipation according to salivary cortisol. Rectal distensions were not associated with a further significant increase in cortisol levels.
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PMID:Pre-experimental stress in patients with irritable bowel syndrome: high cortisol values already before symptom provocation with rectal distensions. 1710 90

Serotonin is an important gastrointestinal signaling molecule. It is a paracrine messenger utilized by enterochromaffin (EC) cells, which function as sensory transducers. Serotonin activates intrinsic and extrinsic primary afferent neurons to, respectively, initiate peristaltic and secretory reflexes and to transmit information to the central nervous system. Serotonin is also a neurotransmitter utilized by a system of long descending myenteric interneurons. Serotonin is synthesized through the actions of 2 different tryptophan hydroxylases, TpH1 and TpH2, which are found, respectively, in EC cells and neurons. Serotonin is inactivated by the serotonin reuptake transporter (SERT)-mediated uptake into enterocytes or neurons. The presence of many serotonin receptor subtypes enables selective drugs to be designed to therapeutically modulate gastrointestinal motility, secretion, and sensation. Current examples include tegaserod, a 5-HT(4) partial agonist, which has been approved for treatment of irritable bowel syndrome (IBS) with constipation in women and for chronic constipation in men and women. The 5-HT(3) antagonists, granisetron and ondansetron, are useful in combating the nausea associated with cancer chemotherapy, and alosetron is employed in the treatment of IBS with diarrhea. Serotonergic signaling abnormalities have also been putatively implicated in the pathogenesis of functional bowel diseases. Other compounds, for which efficacy has not been rigorously established, but which may have value, include tricyclic antidepressants and serotonin selective reuptake inhibitors to combat IBS, and 5-HT(1) agonists, which enhance gastric accommodation, to treat functional dyspepsia. The initial success encountered with serotonergic agents holds promise for newer and more potent insights and therapies of brain-gut disorders.
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PMID:The serotonin signaling system: from basic understanding to drug development for functional GI disorders. 1724 88

While chronic constipation (CC) has a high prevalence in primary care, there are no existing treatment recommendations to guide health care professionals. To address this, a consensus group of 10 gastroenterologists was formed to develop treatment recommendations. Although constipation may occur as a result of organic disease, the present paper addresses only the management of primary CC or constipation associated with irritable bowel syndrome. The final consensus group was assembled and the recommendations were created following the exact process outlined by the Canadian Association of Gastroenterology for the following areas: epidemiology, quality of life and threshold for treatment; definitions and diagnostic criteria; lifestyle changes; bulking agents and stool softeners; osmotic agents; prokinetics; stimulant laxatives; suppositories; enemas; other drugs; biofeedback and behavioural approaches; surgery; and probiotics. A treatment algorithm was developed by the group for CC and constipation associated with irritable bowel syndrome. Where possible, an evidence-based approach and expert opinions were used to develop the statements in areas with insufficient evidence. The nature of the underlying pathophysiology for constipation is often unclear, and it can be tricky for physicians to decide on an appropriate treatment strategy for the individual patient. The myriad of treatment options available to Canadian physicians can be confusing; thus, the main aim of the recommendations and treatment algorithm is to optimize the approach in clinical care based on available evidence.
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PMID:Recommendations on chronic constipation (including constipation associated with irritable bowel syndrome) treatment. 1746 77

The 5-HT(4) partial agonist tegaserod is effective in the treatment of chronic constipation and constipation predominant irritable bowel syndrome. 5-HT(4) receptors are located on presynaptic terminals in the enteric nervous system. Stimulation of 5-HT(4) receptors enhances the release of acetylcholine and calcitonin gene related peptide from stimulated nerve terminals. This action strengthens neurotransmission in prokinetic pathways, enhancing gastrointestinal motility. The knockout of 5-HT(4) receptors in mice not only slows gastrointestinal activity but also, after 1 month of age, increases the age-related loss of enteric neurons and decreases the size of neurons that survive. 5-HT(4) receptor agonists, tegaserod and RS67506, increase numbers of enteric neurons developing from precursor cells and/or surviving in culture; they also increase neurite outgrowth and decrease apoptosis. The 5-HT(4) receptor antagonist, GR113808, blocks all of these effects, which are thus specific and 5-HT(4)-mediated. 5-HT(4) receptor agonists, therefore, are neuroprotective and neurotrophic for enteric neurons. Because the age-related decline in numbers of enteric neurons may contribute to the dysmotilities of the elderly, the possibility that the neuroprotective actions of 5-HT agonists can be utilized to prevent the occurrence or worsening of these conditions should be investigated.
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PMID:Serotonin and neuroprotection in functional bowel disorders. 1762 84

Chronic constipation is a common disorder manifested by a variety of symptoms. Assessments of colonic transit and anorectal functions are used to categorize constipated patients into three groups, i.e., normal transit or irritable bowel syndrome, pelvic floor dysfunction (i.e., functional defaecatory disorders) and slow transit constipation. 'Slow transit' constipation is a clinical syndrome attributed to ineffective colonic propulsion and/or increased resistance to propagation of colonic contents. Defaecatory disorders are caused by insufficient relaxation of the pelvic floor muscles or a failure to generate adequate propulsive forces during defaecation. Colonic transit is often delayed in patients with functional defaecatory disorders. Normal and slow transit constipation are generally managed with medications; surgery is necessary for a minority of patients with slow transit constipation. Functional defaecatory disorders are primarily treated with pelvic floor retraining using biofeedback therapy.
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PMID:Constipation. 1764 10

The gastrointestinal transit can be disturbed in different situations by increased or decreased motility patterns. Pharmacological treatment of gastrointestinal motility disorders is intended to inhibit or stimulate motility. Prokinetic agents as metoclopramide, domperidone, erythromycin or tegaserod are used in clinical settings. We discuss their use in functional dyspepsia and gastroparesis. Management of chronic constipation consists of increasing fluid and dietary fiber intake and increasing physical activity. Fiber, lubricants, osmotic and stimulative laxatives increase stool frequency and improve symptoms of constipation. Treatment of irritable bowel syndrome (IBS) should focuses on the specific gastrointestinal complaints. In constipation predominant IBS fiber and isoosmotic laxatives are used first line. Tegaserod has an advantage over placebo in constipation-predominant IBS. Pain can be treated with antispasmodic agents and tricyclic antidepressants in low doses. The diarrhea-predominant IBS responds well to a loperamide treatment.
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PMID:[Pharmacologic treatments of transit disorders]. 1766 10

Whilst fruits and vegetables are an essential part of our dietary intake, the role of fiber in the prevention of colorectal diseases remains controversial. The main feature of a high-fiber diet is its poor digestibility. Soluble fiber like pectins, guar and ispaghula produce viscous solutions in the gastrointestinal tract delaying small bowel absorption and transit. Insoluble fiber, on the other hand, pass largely unaltered through the gut. The more fiber is ingested, the more stools will have to be passed. Fermentation in the intestines results in build up of large amounts of gases in the colon. This article reviews the physiology of ingestion of fiber and defecation. It also looks into the impact of dietary fiber on various colorectal diseases. A strong case cannot be made for a protective effect of dietary fiber against colorectal polyp or cancer. Neither has fiber been found to be useful in chronic constipation and irritable bowel syndrome. It is also not useful in the treatment of perianal conditions. The fiber deficit - diverticulosis theory should also be challenged. The authors urge clinicians to keep an open mind about fiber. One must be aware of the truths and myths about fiber before recommending it.
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PMID:Fiber and colorectal diseases: separating fact from fiction. 1769 43

Irritable bowel syndrome (IBS) is associated with visceral hypersensitivity, stress and autonomic dysfunction. Sympathetic activity during repeated events indicates excitatory or inhibitory mechanisms such as sensitization or habituation. We investigated skin conductance (SC) during repetitive rectal distensions at maximal tolerable pressure in patients with IBS and chronic constipation. Twenty-seven IBS patients, 13 constipation patients and 18 controls underwent two sets of isobaric rectal distensions. First, maximal tolerable distension was determined and then it was repeated five times. Skin conductance was measured continuously. Subjective symptom assessment remained steady in all groups. The baseline values of SC were higher in IBS patients than in patients with constipation and significantly lower in constipation patients than in controls. The maximal SC response to repetitive maximal distensions was higher in IBS patients compared with constipation patients. The amplitude of the initial SC response decreased successively with increased number of distensions in patients with IBS and constipation but not in controls. Irritable bowel syndrome and constipation patients habituated to maximal repetitive rectal distensions with decreasing sympathetic activity. Irritable bowel syndrome patients had higher sympathetic reactivity and baseline activity than constipation patients. A lower basal SC in constipation patients compared with controls suggests an inhibition of the sympathetic drive in constipation patients.
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PMID:Sympathetic (electrodermal) activity during repeated maximal rectal distensions in patients with irritable bowel syndrome and constipation. 1791 14

Typical and atypical symptoms from acid reflux, dyspepsia, chronic constipation, fecal incontinence, and irritable bowel syndrome are extremely common in adults and remain so in the geriatric population. The presence of these problems may have profound effects on the functional status, independence, and quality of life in the vulnerable older population, making it essential for physicians to inquire actively about them and to be able to recognize atypical presentations when appropriate. This article summarizes the definitions, epidemiology, clinical presentation, and impact of these common problems in the geriatric patient.
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PMID:Chronic gastrointestinal symptoms in the elderly. 1792 34

Functional bowel disorders (FBDs) such as chronic constipation and irritable bowel syndrome-constipation predominant (IBS-C) often share symptoms, but thanks to advances such as the Rome III criteria, diagnosis of these conditions in the absence of alarm features can be relatively straightforward. Empiric treatment is recommended for most patients, with diagnostic testing reserved for those with alarm symptoms. Most current therapies for constipation are indicated for patients with occasional symptoms, with only lubiprostone and tegaserod (restricted) indicated for chronic constipation. Therapies for IBS-C also are limited. However, ongoing research provides promise for improved outcomes in patients with FBDs.
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PMID:Fresh perspectives in chronic constipation and other functional bowel disorders. 1792 91


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