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

We have previously shown that methane on lactulose breath test (LBT) is highly associated with constipation in IBS and that methane gas itself slows small bowel transit in dogs. Previous studies suggest that serotonin may have a role in the control of transit in IBS. In this study, we aim to evaluate the role of serotonin in methane producing IBS subjects. Rome I-positive IBS subjects were recruited into the study after exclusion criteria were met. A fasting LBT was performed after subjects filled out a questionnaire rating the degree of constipation and diarrhea. Within 7 days of this test, subjects returned fasting for determination of serotonin before and after a 75-g oral glucose meal. The serotonin response was compared between hydrogen and methane producing IBS subjects. After 2 subjects were excluded for inadequate blood samples, 18 subjects completed the study. Four of 18 subjects produced methane. The postprandial serotonin level in methane producing IBS subjects was lower than in hydrogen producers (P < 0.05). Methane producers had a reduction in serotonin after glucose. Methane producing IBS subjects have reduced postprandial serotonin. Whether methane is a surrogate marker of constipation or contributing to the reduced serotonin remains to be determined.
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PMID:IBS subjects with methane on lactulose breath test have lower postprandial serotonin levels than subjects with hydrogen. 1499 40

Intolerance to certain foods can cause a range of gut and systemic symptoms. The possibility that these can be caused by lactose has been missed because of "hidden" lactose added to many foods and drinks inadequately labelled, confusing diagnosis based on dietary removal of dairy foods. Two polymorphisms, C/T13910 and G/A22018, linked to hypolactasia, correlate with breath hydrogen and symptoms after lactose. This, with a 48 hour record of gut and systemic symptoms and a six hour breath hydrogen test, provides a new approach to the clinical management of lactose intolerance. The key is the prolonged effect of dietary removal of lactose. Patients diagnosed as lactose intolerant must be advised of "risk" foods, inadequately labelled, including processed meats, bread, cake mixes, soft drinks, and lagers. This review highlights the wide range of systemic symptoms caused by lactose intolerance. This has important implications for the management of irritable bowel syndrome, and for doctors of many specialties.
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PMID:Systemic lactose intolerance: a new perspective on an old problem. 1574 92

Abnormal fermentation may be an important factor in irritable bowel syndrome (IBS). Gastroenteritis or antibiotic therapy may damage the colonic microflora, leading to increased fermentation and the accumulation of gas. Gas excretion may be measured by whole-body calorimetry but there has only been one such study on IBS to date. We aimed to assess the relationship between IBS symptoms and fermentation rates in IBS. A purpose-built, 1.4-m3, whole-body calorimeter was used to assess excretion of H2 and CH4 in IBS subjects while consuming a standard diet and, again, after open randomization on either the standard diet together with the antibiotic metronidazole or a fiber-free diet to reduce fermentation. Metronidazole significantly reduced the 24-hr excretion of hydrogen (median value compared to the control group, 397 vs 230 ml/24 hr) and total gas (H2 + CH4; 671 vs 422 ml/min) and the maximum rate of gas excretion (1.6 vs 0.8 ml/min), as did a no-fiber polymeric diet (hydrogen, 418 vs 176 ml/min; total gas, 564 vs 205 ml/min; maximum rate of gas excretion, 1.35 vs 0.45 ml/min), with a significant improvement in abdominal symptoms. IBS may be associated with rapid excretion of gaseous products of fermentation, whose reduction may improve symptoms.
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PMID:Do interventions which reduce colonic bacterial fermentation improve symptoms of irritable bowel syndrome? 1584 15

In nine studies, 269 healthy subjects or patients underwent exposure to peppermint oil (PO) either by topical intraluminal (stomach or colon) or oral administration by single doses or 2 weeks treatment (n = 19). Methods used to detect effects were oro-cecal transit time by hydrogen expiration, total gastrointestinal transit time by carmine red method, gastric emptying time by radiolabelled test meal or sonography, direct observation of colonic motility or indirect recording through pressure changes or relieve of colonic spasms during barium enema examination. The dose range covered in single dose studies is 0.1-0.24ml of PO/subject. With one exception, which show an unexplained potentiation of neostigmine stimulated colon activity, all other studies result in effects, indicating a substantial spasmolytic effect of PO of the smooth muscles of the gastrointestinal tract. Pharmacokinetic studies reveal that fractionated urinary recovery of menthol is dependent on the kind of formulation used for the application of PO. Optimal pH triggered enteric coated formulations start releasing PO in the small intestine extending release over 10-12 h thus providing PO to the target organ in irritable bowel syndrome, i.e. the colon. The hypothesis is supported by anecdotal observations in patients with achlorhydria or ileostoma, respectively.
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PMID:Gastrointestinal clinical pharmacology of peppermint oil. 1612 22

The presence of methane on lactulose breath test among irritable bowel syndrome (IBS) subjects is highly associated with the constipation-predominant form. Therefore, we set out to determine whether methane gas can alter small intestinal motor function. In dogs, small intestinal fistulae were created to permit measurement of intestinal transit. Using a radiolabel, we evaluated transit during infusion of room air and subsequently methane. In this model, small intestinal infusion of methane produced a slowing of transit in all dogs by an average of 59%. In a second experiment, guinea pig ileum was pinned into an organ bath for the study of contractile activity in response to brush strokes applied to the mucosa. The force of contraction was measured both orad and aborad to the stimulus. The experiment was repeated while the bath was gassed with methane. Contractile activities orad and aborad to the stimulus were significantly augmented by methane compared with room air (P < 0.05). In a third experiment, humans with IBS who had undergone a small bowel motility study were compared such that subjects who produced methane on lactulose breath test were compared with those producing hydrogen. The motility index was significantly higher in methane-producing IBS patients (1,851 +/- 861) compared with hydrogen producers (1,199 +/- 301) (P < 0.05). Therefore, methane, a gaseous by-product of intestinal bacteria, slows small intestinal transit and appears to do so by augmenting small bowel contractile activity.
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PMID:Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity. 1629 52

Hydrogen breath tests are widely used to explore the pathophysiology of functional gastrointestinal disorders. Small intestinal bacterial overgrowth and carbohydrate malabsorption are disorders detected by these tests that have been proposed to be of great importance for symptoms in, for instance, irritable bowel syndrome. However, conclusions drawn from these studies are highly controversial and divergent results exist. There is also an extensive use of these tests in clinical practice with difficulties regarding interpretation of the tests and sometimes erroneous conclusions. The limitations and pitfalls of these tests will be reviewed in this article, and hopefully the occasional abuse of these tests can be turned into proper clinical and scientific use instead in the future.
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PMID:Use and abuse of hydrogen breath tests. 1647

Dietary fructose induces abdominal symptoms in patients with fructose malabsorption, but there are no published guidelines on its dietary management. The objective was to retrospectively evaluate a potentially successful diet therapy in patients with irritable bowel syndrome and fructose malabsorption. Tables detailing the content of fructose and fructans in foods were constructed. A dietary strategy comprising avoidance of foods containing substantial free fructose and short-chain fructans, limitation of the total dietary fructose load, encouragement of foods in which glucose was balanced with fructose, and co-ingestion of free glucose to balance excess free fructose was devised. Sixty-two consecutively referred patients with irritable bowel syndrome and fructose malabsorption on breath hydrogen testing underwent dietary instruction. Dietary adherence and effect on abdominal symptoms were evaluated via telephone interview 2 to 40 months (median 14 months) later. Response to the diet was defined as improvement of all symptoms by at least 5 points on a -10- to 10-point scale. Forty-eight patients (77%) adhered to the diet always or frequently. Forty-six (74%) of all patients responded positively in all abdominal symptoms. Positive response overall was significantly better in those adherent than nonadherent (85% vs 36%; P<0.01), as was improvement in individual symptoms (P<0.01 for all symptoms). This comprehensive fructose malabsorption dietary therapy achieves a high level of sustained adherence and good symptomatic response.
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PMID:Fructose malabsorption and symptoms of irritable bowel syndrome: guidelines for effective dietary management. 1700 Jan 96

Although diarrhea is a common complaint, its evaluation and treatment can be challenging. Appropriately defining and classifying diarrhea provide the framework for approaching diagnostic and therapeutic options. Diarrhea can be defined based on frequency, consistency, and/or weight, and classified as acute or chronic with specific clinical characteristics and stool appearance. Colonoscopy is the most common diagnostic tool used in the evaluation of patients with chronic diarrhea. Other evaluation strategies include timed stool collections, evaluation of inflammatory markers, and hydrogen breath tests. A focused workup of chronic diarrhea may yield a specific diagnosis, including diarrhea-predominant IBS (dIBS), functional diarrhea, diabetic diarrhea, bile acid-induced diarrhea, and microscopic colitis. Ideally, therapeutic decisions are specifically tailored to target the underlying pathophysiology, including, for example, gluten restriction for celiac disease, rotating antibiotics for small bowel bacterial overgrowth, budesonide therapy for collagenous colitis, and loperamide for treatment of functional diarrhea. It is also important to assess the role of diet and medications in chronic diarrhea. However, if no specific causes are identified following workup, empiric therapy with simple opiate antidiarrheals such as loperamide may be effective. If this proves unsuccessful, the use of more potent agents, including codeine and opium, may be considered.
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PMID:A practical approach to treating patients with chronic diarrhea. 1819 62

Although incomplete fructose absorption has been implicated to cause gastrointestinal symptoms, foods containing high fructose corn syrup (HFCS) contain glucose. Glucose increases fructose absorption in healthy subjects. Our hypothesis was that fructose intolerance is less prevalent after HFCS consumption compared to fructose alone in healthy subjects and irritable bowel syndrome (IBS). Breath hydrogen levels and gastrointestinal symptoms were assessed after 40 g of fructose (12% solution) prepared either in water or as HFCS, administered in double-blind randomized order on 2 days in 20 healthy subjects and 30 patients with IBS. Gastrointestinal symptoms were recorded on 100-mm Visual Analogue Scales. Breath hydrogen excretion was more frequently abnormal (P < 0.01) after fructose (68%) than HFCS (26%) in controls and patients. Fructose intolerance (i.e. abnormal breath test and symptoms) was more prevalent after fructose than HFCS in healthy subjects (25% vs. 0%, P = 0.002) and patients (40% vs. 7%, P = 0.062). Scores for several symptoms (e.g. bloating r = 0.35) were correlated (P < or = 0.01) to peak breath hydrogen excretion after fructose but not HFCS; in the fructose group, this association did not differ between healthy subjects and patients. Symptoms were not significantly different after fructose compared to HFCS. Fructose intolerance is more prevalent with fructose alone than with HFCS in health and in IBS. The prevalence of fructose intolerance is not significantly different between health and IBS. Current methods for identifying fructose intolerance should be modified to more closely reproduce fructose ingestion in daily life.
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PMID:Comparison of breath testing with fructose and high fructose corn syrups in health and IBS. 1822 Dec 51

Small intestinal bacterial overgrowth (SIBO) has been implicated in the pathogenesis of irritable bowel syndrome (IBS), although the issue is still under debate. The aim of this study was to determine the prevalence of SIBO in those with IBS and its association with colonic motility, bowel symptoms and psychological distress. Sucrose hydrogen and methane breath tests were performed in 158 IBS patients and 34 healthy controls (HC). Thresholds for pain and urgency were tested by barostat in the descending colon. The motility index (MI) was calculated as the average area under the curve for all phasic contractions. Questionnaires assessed psychological distress, IBS symptom severity (IBS-SS), IBS quality of life (IBS-QOL) and self-reported bowel symptoms. Fifty-two of 158 (32.9%) IBS patients had abnormal breath tests compared with six of 34 (17.9%) HC (chi(2) = 0.079). SIBO (SIBO+) and non-SIBO (SIBO-) patients did not differ in the prevalence of IBS subtypes, IBS-SS, IBS-QOL and psychological distress variables. IBS patients had a greater post-distension increase in MI than HC, but there was no difference between SIBO+ and SIBO- patients. Predominant methane producers had higher urge thresholds (28.4 vs 18.3, P < 0.05) and higher baseline MI (461 vs 301.45, P < 0.05) than SIBO- IBS patients, and they reported more 'hard or lumpy stools' when compared with predominant hydrogen producers (P < 0.05) and SIBO- IBS patients (P < 0.05). SIBO is unlikely to contribute significantly to the pathogenesis of IBS. Methane production is associated with constipation.
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PMID:Small intestinal bacterial overgrowth in irritable bowel syndrome: association with colon motility, bowel symptoms, and psychological distress. 1848 50


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