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

Lactose malabsorption may induce abdominal symptoms indistinguishable from those of the irritable bowel syndrome (IBS), however the exact relationship between the two conditions and the optimal differential diagnostic workup are still to be defined. We prospectively studied the prevalence of lactose malabsorption (by means of a hydrogen breath test) and the clinical effect of a long-term lactose-free diet in 230 consecutive patients with a suggested diagnosis of irritable bowel syndrome, no organic disease of the GI tract, and no history of milk intolerance. Lactose malabsorption was diagnosed in 157 patients (68.2%). In 48 (43.6%) of the 110 patients who complied with the diet symptoms subsided, in 43 they were somewhat reduced and in 17 they remained unchanged. Symptoms never fully subsided in lactose malabsorbers non-compliant with the diet or in normal lactose absorbers who adhered to a lactose-free regimen. Partial improvement was observed in 20% of these subjects. No relation was demonstrated between pre-trial symptoms and the outcome of the diet. The occurrence of symptoms during the lactose breath test strongly suggested a favorable response to diet, but did not help in predicting whether symptoms would subside or be reduced. Conversely, their absence during the test was not associated with an acceptable negative predictive value. The high prevalence of lactose malabsorption in the patients under study suggests that in Italy IBS and lactose malabsorption are frequently associated. A test for diagnosing lactose malabsorption should always be included in the diagnostic workup for IBS and a long-term lactose-free regimen recommended if the test is positive.
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PMID:Lactose malabsorption and irritable bowel syndrome. Effect of a long-term lactose-free diet. 754 19

Antidepressants are used in irritable bowel syndrome (IBS) and may have effects on the gut independent of improving mood. We have investigated the actions of a tricyclic antidepressant on small intestinal motor function in eight healthy volunteers and in six patients with diarrhea-predominant IBS. Fasting ambulatory motility was recorded from six small intestinal sites for 16-18 hr while on no drug (baseline) and while taking imipramine for five days. Orocecal transit time (OCTT) was measured by lactulose hydrogen breath test, during baseline and imipramine administration. Imipramine did not alter migrating motor complex periodicity, but slowed jejunal phase III propagation velocity in controls from 7.5 +/- 1.1 to 3.6 +/- 0.5 cm/min (P < 0.01) and in IBS from 7.8 +/- 0.6 to 4.4 +/- 0.5 cm/min (P < 0.0001). Phase III duration at each site was increased, and total recorded phase III was greater during imipramine than baseline studies. Imipramine increased the amplitude of phase III contractions. There was no effect of imipramine on non-phase-III motility index or discrete clustered contractions. Imipramine, prolonged OCTT from 73 +/- 6 min to 97 +/- 8 min in controls (P < 0.05) and from 61 +/- 9 min to 89 +/- 8 min in IBS (P < 0.05). Although OCTT was shorter in the IBS group, no motility differences were seen between controls and IBS. This demonstration that a tricylic antidepressant can modify small intestinal motor function in health and in IBS supports the view that these drugs may have therapeutic actions in IBS unrelated to mood improvement.
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PMID:Effect of a tricyclic antidepressant on small intestinal motility in health and diarrhea-predominant irritable bowel syndrome. 782 Nov 26

Urinary and/or plasmatic D-xylose tests are broadly used in clinical practice for the diagnosis of intestinal malabsorption. A 5-hr hydrogen breath test (H2 BT) has also proven useful. Our goal was to determine whether a shorter, hence more efficient, 3-hr test would perform as well as the 5-hr test. We studied 33 patients with proven malabsorption, 44 patients with irritable bowel syndrome (IBS), and 27 healthy subjects. Each individual ingested 25 g of D-xylose, and alveolar breath samples were obtained thereafter at 30 min intervals for 5 hr. Breath samples were analyzed for H2 by gas chromatography. Individual peak delta changes and area under the curve (AUC) were calculated. Simultaneously, the 5-hr cumulative urinary excretion of D-xylose was measured by colorimetry. Results of 5-hr tests were compared with those of the first 3 hrs. In the malabsorption group, the 5-hr test showed a markedly enhanced production of H2 relative to healthy controls (delta: 60.7 +/- 6.4 vs 7.7 +/- 1.5 and AUC: 8465.0 +/- 985.4 vs 393.2 +/- 232.6, P < 0.001). Results in IBS patients did not differ from those in healthy controls. Three-hour analysis also reflected an enhanced production of H2 in the malabsorption group (delta: 45.4 +/- 6.4 and AUC: 3700.0 +/- 545.6, P < 0.001 vs healthy controls).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical applicability of shortened D-xylose breath test for diagnosis of intestinal malabsorption. 795 98

This study investigated a possible role for primary bile acid in the control of methanogenesis in the human colon. Production of hydrogen and methane was measured in anaerobic faecal cultures derived from faeces of six 'non-methanogenic' and three methanogenic healthy humans. Using a sensitive technique for gas measurement, methane was detected in all faecal cultures, including those from 'non-methanogenic' humans. Bile acid inhibited methanogenesis in a dose-response fashion in the in vitro 'non-methanogenic' and methanogenic faecal cultures. Inhibition was significant at bile acid concentrations > 0.05%. Methanogenesis correlated with methanogen (methanogenic bacteria) numbers. If this inhibition occurs in vivo, then it would explain much of the epidemiology of non-methanogenesis in humans. From an analysis of net hydrogen production by the faecal cultures, it is inferred that bile acid inhibits other hydrogen-consuming bacteria in addition to methanogens. These in vitro data suggest a major role for bile acid in the accumulation of hydrogen gas in the colon. Possible links between bile acid induced accumulation of gas and irritable bowel syndrome are discussed.
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PMID:A possible role for bile acid in the control of methanogenesis and the accumulation of hydrogen gas in the human colon. 800 41

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation = 13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r = 0.90, P < 0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r = 0.79, P < 0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.
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PMID:Lactulose hydrogen breath test in orocecal transit assessment. Critical evaluation by means of scintigraphic method. 802 63

The effects of octreotide on six normal subjects and five patients with scleroderma were investigated. Changes in intestinal motility and in plasma motilin were examined after a single injection of octreotide. Octreotide stimulated intense intestinal motor activity in normal subjects. Motility patterns in the scleroderma patients were chaotic and non-propagative, but, after octreotide was given, became well coordinated, aborally directed, and nearly as intense as in normal volunteers. Clinical responses and changes in breath hydrogen were also evaluated in the five scleroderma patients who had further treatment with octreotide at a dose of 50 micrograms/day subcutaneously for three weeks. A reduction in symptoms of abdominal pain, nausea, vomiting, and bloating was seen. Additionally, there was an improvement in bacterial overgrowth as objectively measured by breath hydrogen testing. The effects of octreotide (100 micrograms/day subcutaneously) on the perception of rectal distension were investigated in a double blind, placebo controlled study in healthy volunteers. Octreotide was shown to reduce the perception of rectal distension without affecting motor pathways or local rectal reflexes. This enhanced tolerance to volume distension seems to result from inhibition of sensory afferent pathways as shown by electroencephalographic studies showing diminished evoked spinal and cortical potentials after octreotide. In irritable bowel syndrome patients with rectal urgency, octreotide reduces rectal pressures and perception after rectal distension to near normal values.
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PMID:Octreotide in gastrointestinal motility disorders. 820 95

Disturbances of small bowel motor function are increasingly recognized in clinical practice, either in the setting of an underlying disease that may affect the neuro-hormonal control of gut motility, such as diabetes or scleroderma, or as part of unexplained intestinal dysfunctions such as the irritable bowel syndrome or chronic idiopathic intestinal pseudo-obstruction. In the absence of endoscopic or radiological mucosal disease, it is often clinically helpful to define the motor function of the small bowel to understand the origin of the patient's symptoms. The hydrogen breath test after a lactulose oral load is currently used to measure mouth to caecum transit time. However, the reproducibility of this test is poor, and the range of normal values is wide. Scintigraphic determination of small intestinal transit time overcomes some of the limitations of the hydrogen breath test. This is however a time consuming procedure--up to 10 hrs when the time for acquisition, processing and analysis is included--and the costs prohibit widespread application of the technique. It is further restricted by the exposure to ionising radiation, particularly if repeated evaluations are necessary, for example in drugs trials. Manometry records mechanical activity of the bowel and detects quantitative and qualitative changes of small intestinal motility. As with scintigraphy, high costs and radiation exposure limit its usefulness. The major clinical application of the technique is in the diagnosis of chronic intestinal pseudo-obstruction.
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PMID:[Evaluation of small intestinal motility]. 821 Oct 47

Hydrogen breath tests (H2 BT) have been used extensively to investigate intestinal disaccharidase deficiencies. A potentially useful test for assessing intestinal absorptive function, the H2 BT with D-xylose (H2 BT-D-xylose), has received scant attention. We report here the results of our investigation of this test in 45 patients. Fifteen patients had proved malabsorption that was due to nontropical sprue in nine, and to lymphoma, Whipple's disease, or giardiasis in the remainder. Nine patients had small-bowel bacterial overgrowth secondary to either postsurgical sequelae or intestinal dysmotility. Twenty-one patients with irritable bowel syndrome and 21 healthy individuals served as control groups. All participants ingested 25 g of D-xylose, and alveolar breath samples were obtained thereafter at 30 min intervals for 5 hr. Breath H2 was measured by chromatography. Basal H2 production, peak change (delta) and area under the curve (AUC) were calculated. Simultaneously, 5-hr urinary excretion of D-xylose was measured by colorimetry and served as the reference test. In healthy individuals, D-xylose ingestion increased H2 production (delta = 5.8 +/- 1.4 ppm, P < 0.001). Changes were similar in patients with the irritable bowel syndrome. In contrast, the increase was of a much greater magnitude in the malabsorption group (delta = 49.9 +/- 7.2 ppm, P < 0.001 vs healthy controls). AUC analysis yielded comparable results. Test performance analysis showed that, in malabsorption the H2 BT-D-xylose had a sensitivity index of 0.86, which was identical to that of the urinary D-xylose test. Specificity was 1 and 0.95, respectively; and predictability 1 and 0.93, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Potential usefulness of hydrogen breath test with D-xylose in clinical management of intestinal malabsorption. 842 44

Patients who met International Congress of Gastroenterology criteria for irritable bowel syndrome (IBS) and had breath hydrogen lactose testing were interviewed to determine whether detection of lactose maldigestion (LM) had an impact on their symptoms. Of 199 patients initially evaluated, 161 (81%) were contacted and asked to rate their symptoms. At baseline, 47 (29%) of the IBS group had LM. Before testing, 23 (49%) were aware that ingestion of lactose-containing food was associated with their gastrointestinal symptoms. Lactose-maldigesting IBS subjects (IBSLM, n = 47) and those who had IBS and no LM (n = 114) were similar in terms of age, sex, and ethnic background. Interviews performed 41 +/- 1.1 (SEM) months after baseline evaluation revealed no significant differences in abdominal pain, altered bowel habits, bloating/distension, mucus, and relief with defecation among those with IBS or LMIBS. Overall symptoms resolved, improved, did not change, or worsened in a manner not statistically different between IBS and IBSLM groups. IBSLM subjects (a) felt that identifying LM helped them gain awareness of food-symptom relationships (78.7%), (b) experienced some improvement in symptoms (83%), (c) were avoiding lactose foods (87.2%), or (d) used lactase enzyme supplements (38.3%). Identifying LM did not significantly affect rated variables.
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PMID:Does lactose maldigestion really play a role in the irritable bowel? 883 92

The common occurrence of irritable bowel syndrome underscores the importance of an accurate diagnostic evaluation without unnecessary expense. A preliminary diagnosis can usually be made with the Manning symptom criteria and additional history data in patients without warning signs of organic disease. A confident diagnosis can often be made with the addition of a physical examination and only limited laboratory and structural studies, such as a proctosigmoidoscopy and complete blood count. Tests that may be indicated in some patients include fecal examination for parasites and occult blood, dietary lactose exclusion or a lactose-hydrogen breath test, and a complete colon structural study. Other tests are occasionally indicated. Routine rectal biopsy and abdominal ultrasonography are unnecessary in patients with only typical symptoms, and large bowel motility testing is not useful. After a confident diagnosis, further testing for recurrent symptoms can be minimized. Investigation for psychosocial factors, while not necessary to diagnose irritable bowel syndrome, is important in treatment and may reduce medical costs. Misdiagnosis can result in unnecessary hysterectomy and other surgery, and it may be reduced by closer collaboration with gynecologists and general surgeons in the evaluation of patients.
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PMID:Irritable bowel syndrome. Diagnosis in the managed care era. 920 Oct 69


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