Lactulose hydrogen breath test in orocecal transit assessment

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.     

Orocaecal transit time in health and in thyroid disease.

Altered bowel habit commonly occurs in thyroid disease. We measured orocaecal transit in healthy volunteers and in hyperthyroid and hypothyroid patients before and after treatment, using the lactulose hydrogen breath test incorporating a standard liquid meal to obtain a more physiological assessment. Mean transit time in 12 control subjects was 85 (8) minutes (mean (SE)) (mean coefficient of variation between replicate studies, 8.6% (3%)). In eighteen hyperthyroid patients transit was more rapid at 49 (4) minutes (p less than 0.01). Ten hypothyroid patients had a transit time similar to controls at 91 (9) minutes. Transit time returned to normal in thyrotoxic patients after treatment but in eight hypothyroid patients retested, it remained unchanged. Our findings suggest that (a) the inclusion of a liquid meal provides a reproducible method of measuring orocaecal transit using the lactulose hydrogen breath test, (b) rapid small bowel transit in thyrotoxicosis may be one factor in the diarrhoea which is a feature of the disease and (c) if altered gut transit is the cause of sluggish bowel habit in hypothyroidism, delay in the colon, and not small bowel, is likely to be responsible.     

Measurement of gastric emptying, intestinal transit time and colonic filling by scintiscan in healthy subjects

A scintigraphic technique allowing combined measurements of gastric emptying, small intestinal transit time and colonic filling was developed and its reproducibility assessed in 8 healthy volunteers. Each subject underwent four tests: a) two were performed in the fasting state (99mTc labelled water, added to lactulose), b) two in the postprandial state (balanced meal, 1,750 kJ, included pellets labelled with 111In, the gut transit of which being nearly the same as dietary fibers). Intestinal transit was modeled using linear operators (expressed as a convolution product). In fasting state (lactulose), orocecal transit time of water was 109 +/- 60 min and 89 +/- 36 min (m +/- DS) for the first and second tests, respectively. In the postprandial state, values were 297 +/- 37 min and 293 +/- 43 min respectively for the pellets. Small bowel transit times were 135 +/- 70 and 103 +/- 40 min respectively in fasting state for water, and 209 +/- 47 and 209 +/- 29 min respectively in postprandial state for the pellets. Determination of residual variance showed that reproducibility of the test was better in the postprandial state than in the fasting state. Water orocecal transit times measured using this technique and lactulose orocecal transit time measured using hydrogen breath test were strongly correlated (r = 0.98, n = 12, P less than 0.01). This isotopic method provides a reproducible assessment of gastric emptying, small bowel transit, and colonic filling and could represent a reliable and non invasive tool for further physiological and pharmacological studies.     

Limitations of indirect methods of estimating small bowel transit in man

Experiments were carried out in healthy volunteers to explore the utility of a new [14C]lactulose breath test for measuring small intestinal transit time in man and to use this procedure to test whether two antidiarrheal agents, codeine and clonidine, alter small intestinal transit time during digestion of a liquid meal. In an initial validation study performed in 12 subjects (three studies in each subject), a liquid test meal containing 10 g [14C]lactulose was administered and the colonic entry time estimated from the time course of 14CO2 excretion in breath compared with that of H2 excretion. There was a fair correlation (r = 0.77; P less than 0.001) between results obtained by the two methods; both methods gave similar results, but 14CO2 output was delayed when compared to H2 output and was incomplete. The meal also contained xylose and [13C]glycine, permitting the duodenal entry time of the meal to be estimated by the appearance of xylose in blood and 13CO2 in breath, respectively. The same liquid meal was then used to examine the effect on small intestinal transit time (colonic entry time minus duodenal entry time) of codeine or clonidine. 99Tc-sulphur colloid was also added to the meal to permit a comparison of small intestinal transit estimated by imaging with that estimated by the 14CO2-lactulose breath test. 99Tc radioactivity appeared in the cecum (as assessed using gamma scintigraphy) about 2 hr before 14CO2 radioactivity appeared in breath; the correlation between transit time estimated by the two methods was moderate (r = 0.61; P less than 0.05). Based on the [14C]lactulose data, small intestinal transit time ranged from less than 1 to 3 hr for a liquid meal containing 10 g lactulose; within-subject variation (coefficient of variation 17%) was considerably less than between-subject variation (coefficient of variation 56%). Codeine increased the small intestinal transit time significantly (from 2.7 +/- 0.3 hr to 5.0 +/- 0.9 hr; mean +/- SE), whereas clonidine did not alter small intestinal transit time, as estimated by the colonic entry time minus duodenal entry time. Neither drug influenced duodenal entry time. These results suggest that the [14C]lactulose breath test, which has only moderate accuracy, may have occasional utility as a convenient, noninvasive method for estimating small intestinal transit time in man. However, this study also suggests that indirect methods of estimating small bowel transit in man have limitations, variability, and possibly may lack the desired sensitivity.     

Lactose malabsorption, irritable bowel syndrome and self-reported milk intolerance

BACKGROUND: The relationship between lactose malabsorption, irritable bowel syndrome and development of intestinal symptoms is unclear, especially when the ingested dose of milk is small. Thus, the role of hydrogen breath testing in the diagnostic work-up of patients with nonspecific intestinal symptoms is still debated. AIMS: To establish the relationship between lactose malabsorption, severe self-reported milk intolerance, irritable bowel syndrome and related symptoms. METHODS: The prevalence of lactose malabsorption was prospectively assessed by means of a hydrogen breath test in 839 patients (503 with irritable bowel syndrome, based on the Rome criteria, regularly consuming milk, and 336 subjects who identified themself as milk intolerant, after an oral load of 25 g lactose). The test was considered "positive" when a hydrogen peak exceeding 20 ppm over baseline values was observed in two or more samples. Attempts were also made to establish whether the predominant presenting symptom (diarrhoea, constipation, alternating diarrhoea and constipation, pain and gaseousness) might be helpful in predicting the outcome of the breath test. RESULTS: The prevalence of a positive breath test was comparable in the two groups (337 patients with irritable bowel syndrome (66.9%) vs 240 patients with milk intolerance (71.4%)). The same holds true for the first peak of hydrogen excretion, total hydrogen output and prevalence of symptoms during, and in the four hours after, the test. The predominant presenting symptom was not useful for predicting outcome of the test either in regular milk users or in milk intolerant subjects. CONCLUSIONS: The almost identical results of the lactose breath test of patients with irritable bowel syndrome and subjects with self-reported milk intolerance suggests that the two conditions overlap to such an extent that the clinical approach should be the same. A lactose breath test should always be included in the diagnostic work-up for irritable bowel syndrome, as fermentation of malabsorbed lactose is likely responsible for triggering symptoms. Conversely, lactase deficiency is probably irrelevant in most subjects not affected by irritable bowel syndrome, within a moderate milk consumption.     

Methodological aspects of the use of the hydrogen (H2) breath test

Normalization of the breath hydrogen (H2) concentration by simultaneous determination of breath carbon dioxide (CO2) and the addition of lactulose to a liquid meal have been recommended to improve the reproducibility of the hydrogen breath test. To assess the clinical relevance of these recommendations, we studied 64 children of 4 different age groups and 12 adults. Simultaneous determination of CO2 concentration and normalization of breath H2 resulted in a marked decrease of intestinal transit time and its variation in children; in adults, however, this correction was negligible. With lactulose alone, the mean coefficient of variation within individuals was only 11.7% and 13.2%, with and without H2 normalization, respectively. Therefore, the addition of a liquid meal does not seem to be necessary.     

Gluten-Free Diet Normalizes Mouth-to-Cecum Transit of a Caloric Meal in Adult Patients with Celiac Disease

The mechanisms responsible for boweldisturbances in celiac disease are still relativelyunknown. Recent reports suggested that small bowel motorabnormalities may be involved in this pathologicalcondition; however, there are no studies addressing smallbowel transit in celiac disease before and after agluten-free diet. We studied the mouth-to-cecum transittime of a caloric liquid meal in a homogeneous group of celiac patients presenting with clinical andbiochemical evidence of malabsorption and complaining ofdiarrhea. Sixteen patients were recruited andinvestigated by means of hydrogen breath test through ingestion of 20 g lactulose together with anenteral gluten-free diet formula. A urinary D-xylosetest was also done in each patient. Both breath testsand D-xylose tests were carried out basally and after a period of gluten-free diet. Twenty healthyvolunteers were recruited as a control group andunderwent the same breath testing. At the time of thediagnosis, mouth-to-cecum transit time was significantly prolonged in celiacs with respect to controls(243 ± 10 vs 117 ± 6 min, P = 0.0001). TheD-xylose test was also abnormal (average urinaryconcentration 2.8 ± 0.25 g, normal values>4.5). No correlation was found in patients between mouth-to-cecum transit timeand urinary D-xylose output (r = 0.22). After thegluten-free diet period, mouth-tocecum transit time inceliacs was significantly reduced compared to prediet transit (134 ± 8 vs 243 ± 10 min,P = 0.0001) and did not show statistical difference whencompared to that found in controls (P = 0.1). TheD-xylose test reverted to normal in all but twosubjects, who were found to be noncompliant with the diet.Mouth-to-cecum transit time is significantly prolongedin patients affected by untreated celiac disease whencompared to healthy controls. This alteration might notbe correlated to intestinal malabsorption, and theprolonged orocecal transit could be due to impairedsmall bowel function (deranged motility?). Sinceintestinal transit returned to normal values after an adequate gluten-free period, a link with severeactive mucosal lesions is suggestive.     

Assessment of the reproducibility of the lactulose H2 breath test as a measure of mouth to caecum transit time

The lactulose H2 breath test is in use as a simple non-invasive measurement of mouth to caecum transit time, but its reproducibility has never been assessed. We have examined the reproducibility of mouth to caecum transit time in 21 normal subjects using lactulose 10, 15, and 20 g; seven subjects being studied with 10 g and 12 each with 15 and 20 g doses. Transit time decreased with increasing doses of lactulose although the differences were not significant between or within (n = 5) individuals. Variation in transit times between individuals was considerable with all doses of lactulose (mean coefficient of variation of 18.5, 29.7 and 28.3% with 10, 15, and 20 g respectively). The addition of lactulose to a liquid meal containing carbohydrate, fat, and protein decreased the coefficient of variation to less than 10% in four subjects studied. The lactulose H2 breath test could be made more reproducible by including a liquid meal.     

Statistical analysis of the lactulose/breath hydrogen test in the measurement of orocaecal transit: its variability and predictive value in assessing drug action.

The variability in the orocaecal transit time as measured by the lactulose/breath hydrogen method has been studied for three conditions: lactulose given with a meal, subjects sitting; lactulose given with a meal, subjects semirecumbent; lactulose given in aqueous solution, subjects semirecumbent. Thirty three healthy subjects attended on up to 12 occasions. It was found that administration of the lactulose with a meal significantly reduced the variability (p less than 0.05) and that adoption of the semirecumbent position further reduced variability. A power analysis was used to predict the number of subjects who would be required to show a given percentage change in orocaecal transit time at specified probabilities and powers. A graph and a table for use in the prediction of subject numbers at a probability of 5% and for powers of 50-99% is presented. A dose response curve for metoclopramide using the lactulose/breath hydrogen method is given for doses of 10, 15, and 20 mg.     

Mouth to pouch transit after restorative proctocolectomy: hydrogen breath analysis correlates with scintigraphy

OBJECTIVES: Fast intestinal transit may be responsible for slow adaptation and unacceptable steady-state function after restorative proctocolectomy. Investigation of GI transit time may be valuable in such a setting. We hypothesized that postprandial hydrogen breath tests may yield transit data that correlate with technetium-labeled meal scintigrams. METHODS: This study compared intestinal transit after a lactulose and bean meal via the breath hydrogen and scintigraphy methods in 21 ileoanal pouch subjects. The meal consisted of baked beans (425 g), 30 ml (20 g) lactulose syrup, 1 mCi 99mtechnetium sulfur colloid in finely chopped liver and 170 ml tap water. The meal contained 120 Kcal (70% carbohydrate, 18% protein and 12% fat). RESULTS: Of 21 pouch subjects, 11 (53%) had breath tests and scintigraphy transit studies that differed by 5-21 min. Three of 21 (14%) scintigraphy mouth to pouch transit times were faster than breath test transits by 43-107 min. Seven of 21 (33%) subjects did not have breath test peaks >10 ppm. Mouth to pouch transit for breath hydrogen (104+/-16 min) and scintigraphy (98+/-7 min) tests had significant correlation (r = 0.96, p < 0.0001) among subjects with alveolar hydrogen peaks and accurate scintigrams (n = 11). Scintigrams were five times more expensive than breath tests. CONCLUSIONS: A peaking hydrogen breath test provides an alternative to scintigraphy for estimating intestinal transit after ileoanal pouch.     

Diagnostische Evaluation der D��nndarmmotilit?t

Investigations of small bowel motility are performed relatively infrequently partly because of impaired accessibility of the small bowel. For diagnostic evaluation transit measurements and manometric techniques are generally available. Scintigraphy is regarded as the reference method for evaluation of small bowel transit but is rarely performed in Europe. Clinically, the lactulose hydrogen breath test is most frequently used for estimation of orocecal transit time. Apart from this radiological techniques can be used to roughly estimate small bowel transit. Capsule techniques and the lactulose-¹³C-ureide breath test represent potential alternatives. In contrast to transit measurements small bowel manometry reveals information on the contractile patterns of the small bowel and thus on pathophysiological mechanisms. However, small bowel manometry is relatively complex and labor-intensive and is therefore reserved for special indications and specialized centres.     

Lactose malabsorption in Greek adults: correlation of small bowel transit time with the severity of lactose intolerance.

Using breath hydrogen analysis after 139 mmol (50 g) oral lactose load, we investigated the prevalence of lactose malabsorption in 200 Greek adults and examined the relationship between symptoms and small bowel transit time. One hundred and fifty subjects had increased breath hydrogen concentrations (greater than 20 ppm) after the lactose load. In these individuals peak breath hydrogen concentration was inversely related to small bowel transit time (r = 0.63, 6 = 6.854, p less than 0.001) and the severity of symptoms decreased with increasing small bowel transit time. Lactose malabsorbers with diarrhoea during the lactose tolerance test had a small bowel transit time of 51 +/- 22 minutes (x +/- SD; n = 90) which was significantly shorter than the small bowel transit time of patients with colicky pain, flatulence, and abdominal distension (74 +/- 30, n = 53; p less than 0.001) and both groups had significantly shorter small bowel transit time than that of asymptomatic malabsorbers (115 +/- 21 n:7; p less than 0.001). When the oral lactose load was reduced to 33 mmol (12 g), the small bowel transit time increased five-fold and the overall incidence of diarrhoea and/or symptoms decreased dramatically. These results indicate that the prevalence of lactase deficiency in Greece may be as high as 75% and suggest that symptom production in lactose malabsorbers is brought about by the rapid passage down the small intestine of the malabsorbed lactose.     

Breath hydrogen as a test for gastrointestinal transit

Intestinal transit is an important indicator of small-bowel function. This study served to investigate oro-cecal and duodeno-cecal transit times of different carbohydrate test meals and to evaluate intra- and interindividual variability of the breath hydrogen test. Breath hydrogen was analysed by an electrochemical cell in 25 healthy volunteers. Oro-cecal transit time of lactulose was much shorter than that of a standardized normal test meal. Duodeno-cecal transit was approximately one hour shorter than oro-cecal transit. Considerable intra- and interindividual differences were observed. It is concluded that results of lactulose test meals do not permit conclusions as to the physiological situation. Large intra- and interindividual variability of transit times must be taken into account in any study using the breath hydrogen test.     

COLIGENTA treatment of small intestinal bacterial overgrowth. Results of an open study.

PurposeThe treatment of small intestinal overgrowth (SIBO) varies according to the center. The present study aimed to evaluate the efficacy of COLIGENTA, an association of colimycin and gentamycin, on SIBO symptomatology and breath test normalizationPatients and MethodsIn this prospective cross-sectional open study, 150 patients with functional bowel disorders and SIBO diagnosed by lactulose hydrogen breath test (LHBT) underwent COLIGENTA oral treatment. A new HLBT was performed 4 weeks after the first HLBT.ResultsThe patients were mainly female (74%), with a mean age of 47.4 ± 16.2 years and a body mass index of 26.2 ± 5.9 kg/m². After treatment, a decrease of expired hydrogen concentration (P<0.001) was found in the entire population. Improvement of gastrointestinal symptoms was found in 129 patients (86%), while the breath test's normalization was found in 62 patients (42%). Logistic regression showed that normalization of bowel symptoms was not associated with demographics, clinical, or hydrogen breath concentration. In contrast, normalization of LHBT was associated with an increase of breath hydrogen concentration at time 100 min during the first test (P = 0.003; OR=1.072; 95%CI= [1.023–1.123]).ConclusionThe present study shows that 10-days of COLIGENTA treatment has a high SIBO clinical improvement rate and can be used as the first or second treatment line.     

Lactase deficiency and lactose intolerance-related symptoms in adult healthy subjects from western France]

The prevalence of lactase deficiency (LD) and lactose intolerance is not well known in France. Using breath hydrogen and methane analysis after 50 g oral lactose load, we investigated the prevalences of LD, lactose intolerance, and methane producer status in 102 healthy adults born in western France, and we examined the relationships between these parameters and the daily milk consumption. In 10 subjects with LD and lactose intolerance, we studied the reproducibility of the lactose hydrogen breath test results for the diagnosis of LD and lactose intolerance and estimated the quantity of lactose malabsorbed in comparison with the lactulose hydrogen breath test. The prevalence of LD was 23.4 percent and symptoms of lactose intolerance were observed in 50 percent of the 24 subjects with LD. The daily milk consumption was not significantly different in the 24 subjects with LD and in the 78 subjects without LD (281 +/- 197 vs 303 +/- 217 ml/24 h). The prevalence of methane producer status was 42.1 percent. The symptomatic group of lactose malabsorbers (n = 12) was characterized by a shorter lactose mouth to caecum transit time (39 +/- 20 vs 88 +/- 48 min; P less than 0.05), and more marked hydrogen production (6.1 +/- 2.3 vs 3.4 +/- 2.4 10(3) ppm.min; P less than 0.04). In the 10 subjects with LD and lactose intolerance, the hydrogen breath test was reproducible for diagnosis of LD and lactose intolerance, and for hydrogen production. The quantity of lactose malabsorbed was 60 percent. In France, symptoms of lactose intolerance are not severe and do not affect the daily consumption of milk and dairy products.     

Reproducibility of orocecal transit time and hydrogen production measured by breath tests]

The hydrogen breath test after a lactulose oral load in the fasting period is currently used to measure mouth to cecum transit time (MCTT). However, the reproducibility of this test is poor, and normal values are very scattered. The aim of the study was to determine the reproducibility of hydrogen breath test for MCTT measurement and hydrogen production after administration of 2 disaccharides: lactulose and lactitol ingested in the fasting state and postprandial period. Twelve healthy volunteers (6 men and 6 women; mean age = 34.6 +/- 9.6 years) were studied eight times in a random order, each disaccharide being studied twice in the fasting state and twice in the postprandial period. In the later, lactulose or lactitol was ingested 30 min after a liquid meal completely absorbed (400 kcal; glucide: 55 p. 100, lipid: 30 p. 100, protein: 15 p. 100; 400 ml of Inkopeptide). The MCTT was significantly increased with both disaccharides in the postprandial period as compared with the fasting state (P less than 0.0001). There was nos significant correlation between the 2 measurements of the MCTT in the fasting state, in contrast, the 2 measurements of the MCTT were closely related in the fed state (r = 0.62, P less than 0.05, et r = 0.79, P less than 0.003 for lactulose and lactitol respectively). During both periods no significant difference was found in the MCTT between lactulose and lactitol. As well, hydrogen production did not differ between the 2 disaccharides, but was significantly increased in the postprandial period, and in non methane producers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of Scintigraphy and Lactulose Breath Hydrogen Test for Assessment of Orocecal Transit (Lactulose Accelerates Small Bowel Transit)

The lactulose breath test (LBT) andgastroenterocolonic scintigraphy (GECS) can both be usedto measure orocecal transit time (OCTT). The aims ofthis study were (1) to measure OCTT by LBT and GECS and (2) to determine whether lactulose altersorocecal transit. Methods: Eight normal subjectsunderwent simultaneous breath hydrogen testing, GECS,and duodenal manometry while receiving either 10 glactulose or placebo with a radiolabeled solid/liquidtest meal during two studies. There was a goodcorrelation between OCTT by LBT and GECS when performedsimultaneously (r = 0.95; P < 0.001). OCTT by GECSwith lactulose was significantly faster (P = 0.004) than byGECS without lactulose, despite no change in gastricemptying of liquids and slowing of gastric emptying ofsolids (P = 0.02). The postprandial duodenal motility index was greater with lactulose than withplacebo (P = 0.031). This study demonstrates that LBTand GECS (without lactulose) are not equivalent measuresof OCTT. The standard LBT accelerates OCTT and slows gastric emptying. Therefore, lactulose has adirect accelerating effect on small intestinaltransit.     

Small bowel transit time and colonic fermentation in young and elderly women

Small bowel transit time (SBTT) in 15 young and 13 elderly women was assessed by measuring breath hydrogen concentrations after they had consumed a solid test meal. The meal consisted of 200 g cooked rice, 50 mlmiso (made from fermented soy bean curd) soup, a boiled egg, and 95.5 g of cooked soy beans with mixed vegetables. This meal provided 17 g protein, 14.1 g fat, 92.9 g carbohydrate, 7 g dietary fiber, and 565 kcal total energy. The SBTT, calculated by a 3 ppm increase in breath hydrogen, was 19±14.9 (mean±SE) min in the young and 188.1±16.8 min in the elderly group; the difference was not significant. Breath hydrogen levels, however, were higher in the young than in the elderly group (39.1±6.3 ppm, vs 22.2±4.3 ppm,P<0.05). There was an initial peak of hydrogen concentration, reached almost immediately after the ingestion of the meal, and then a decline to baseline within 60 min. This initial peak was not as pronounced in the elderly subjects. A second peak, indicating the entry of the test meal into the cecum, was more pronounced in the young than in the elderly group. SBTT did not differ significantly between the two groups, but colonic fermentation was more pronounced in the young, both in the fasting and the postprandial state.     

Repeatability of lactulose hydrogen breath test in subjects with normal or prolonged orocecal transit

The within-subject repeatability of orocecal transit assessed with lactulose hydrogen breath test was evaluated in 15 healthy volunteers and 16 constipated or obese patients. The test was repeated twice in each subject. Mean (SD) transit time was 105 (63) and 103 (60) min in the first and second series of tests, respectively, showing that the first measurement did not affect the second. The within-subject repeatability of the test was related to the length of transit, the scatter of the differences between the first and second test being greater with the increase of the mean gastrointestinal transit time. The 95% coefficient of repeatability was 84 min for all measurements and 30 and 118 min, respectively, for transit times under and over 100 min. The lowest reproducibility of the test was found in constipated patients with prolonged orocecal transit.     

Lactulose hydrogen and [14C]xylose breath tests in patients with ileoanal anastomosis

To study the intestinal bacterial flora and mouth to pouch transit time after ileoanal anastomosis, lactulose hydrogen and [¹⁴C]xylose breath tests were performed on 19 patients with ileoanal anastomosis and J-pouch and 8 patients with conventional ileostomy. Evaluated by the [¹⁴C]xylose breath test, patients with ileoanal anastomosis and ileal pouch showed no difference in the bacterial flora of the proximal small bowel when compared with ileostomy patients. The lactulose hydrogen breath test showed a significant rise in breath hydrogen, indicating bacterial overgrowth, in 68% of patients with ileoanal anastomosis but in none with conventional ileostomy (p<0.01). It was concluded that this peak in breath hydrogen was produced by the bacteria in the pouch. Thus the lactulose hydrogen breath test can be used to measure mouth to pouch transit time in 2/3 of patients with ileoanal anastomosis. Mouth to pouch transit time was 63±9 min and it correlated inversely with stool frequency (p<0.05).

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Résumé Pour étudier la flore intestinale bactérienne et le temps de transit bucco-anal après anastomose iléo-anale des tests respiratoires au lactulose hydrogène C14 xylose ont été réalisés chez 19 patients avec anastomose iléoanale et poche en J et chez 8 malades avec une iléostomie conventionnelle. Lors du test C14 xylose il n'y avait aucune différence en ce qui concerne la flore bactérienne de l'intestin grèle proximal chez les malades qui avaient une anastomose iléo-anale avec poche et chez ceux qui avaient une iléostomie. Le test au lactulose hydrogène montrait une augmentation significative de l'hydrogène respiratoire indiquant une pullulation bactérienne chez 68% des malades avec anastomose iléo-anale mais chez aucun de ceux qui avaient une iléostomie conventionnelle (p<0.01). On conclue que le pic d'hydrogène respiratoire était produit par les bactéries dans la poche. Ainsi le test au lactulose hydrogène respiratoire peut être usé pour mesurer le temps de transit bouche-poche chez 2/3 des patients avec une anastomose iléo-anale. Le temps de transit bouche-poche était de 63±9 mn et était corrélé inversement avec la fréquence des selles (p<0.05).