Hydrogen breath test--diet and basal H2 excretion: a technical note.

BACKGROUND: Hydrogen breath tests are widely used in clinical practice. For a correct evaluation of data, low basal H2 excretion is required, thus, 12-hour fasting is usually prescribed. An additional reduction in the intake of complex carbohydrates in the preceding 24 h is suggested in some centers. The issue, however, has never been directly investigated. AIM: The aim of the present study was to analyze the effect of the pretest diet on the basal H2 excretion and the number of subjects excluded from the test due to high basal H2 excretion. METHODS: Two cohorts of 500 consecutive patients undergoing a lactose tolerance test in the years 1997-1998 (when 12-hour fasting was required) and in 2007-2008 (when a low-carbohydrate diet in the preceding 24 h was also prescribed) were retrospectively reviewed. RESULTS: The mean basal H2 excretion was significantly lower (p < 0.0001) in the low-carbohydrate diet group (2.46 +/- 6.8 vs. 4.73 +/- 3.3 ppm). In 1997-1998, 46/500 patients (9.2%) were excluded from the test due to basal H2 values as compared to 7/500 (1.4%) in the period 2007-2008. DISCUSSION: To the best of our knowledge, ours is the first study to provide objective data on the advantage offered by reducing the intake of complex carbohydrates before H2 breath tests.

Short-chain fatty acid topical treatment in distal ulcerative colitis.

BACKGROUND: Some evidence indicates that short-chain fatty acid (SCFA) enemas are effective in the treatment of distal ulcerative colitis. METHODS: In a randomized, double-blind, placebo-controlled study, we tested the efficacy of a 6-week course of topical SCFA (100 mL, twice daily enemas of sodium acetate 80 mmol/L, sodium propionate 30 mmol/L and sodium butyrate 40 mmol/L) in 40 patients with mild to moderate distal colitis. Clinical, endoscopic and histological data were collected at the beginning and end of the study. RESULTS: Fourteen patients on SCFA improved (overall score 11.3 +/- 2.0 vs. 7.4 +/- 3.5) as compared to five in the placebo group (overall score 10.0 +/- 1.9 vs. 8.9 +/- 2.5). In the SCFA-treated group all parameters significantly improved except the number of bowel motions, whereas no significant changes were recorded in the control group. A statistically significant difference between the two treatment regimens, however, was observed only for intestinal bleeding (P < 0.05), urgency (P < 0.02) and the patient self-evaluation score (P < 0.05). This was probably due to the random inclusion of more patients with moderate disease into the SCFA-treated group, thus causing pretrial differences between the two groups. CONCLUSION: The present study confirms that irrigation with SCFA enemas is effective in distal colitis, and may represent an alternative therapeutic tool in the treatment of the disease.

Infliximab in refractory pouchitis complicated by fistulae following ileo-anal pouch for ulcerative colitis.

AIM: To determine the efficacy of infliximab in the treatment of chronic refractory pouchitis complicated by fistulae following ileal pouch-anal anastomosis for ulcerative colitis. METHODS: This open study included seven patients (four females, three males) with chronic refractory pouchitis complicated by fistulae. Pouchitis was diagnosed by clinical, endoscopic and histological criteria. The sites of the fistulae were as follows: pouch-bladder in one, vaginal in three, perianal in two, and both vaginal and perianal in one. Extra-intestinal manifestations (erythema nodosum, arthralgia) were present in four patients. Crohn's disease was carefully excluded in all patients after re-evaluation of the history, re-examination of the original proctocolectomy specimen and examination of the proximal small bowel. All patients had been treated with antibiotics and three with steroids. Patients received infliximab, 5 mg/kg, at 0, 2 and 6 weeks. Azathioprine (2.5 mg/kg) was also started for all patients as bridge therapy. Clinical response was classified as complete, partial or no response. Fistulae closure was classified as complete (cessation of fistulae drainage and total closure of all fistulae), partial (a reduction in the number, size, drainage or discomfort associated with fistulae) or no closure. The pouchitis disease activity index and quality of life were also used as outcome measures. RESULTS: Clinically, all patients improved. At the 10-week follow-up, six of the seven patients had a complete clinical response, and five had complete fistulae closure. At the 10-week follow-up, the median pouchitis disease activity index decreased from 12 (baseline) (range, 10-15) to 5 (range, 3-8); the median quality of life decreased from 37 points (range, 33-40) to 14 (range, 9-18). Erythema nodosum and arthralgia showed complete remission soon after the first infusion of infliximab. CONCLUSIONS: These preliminary results indicate that infliximab may be recommended for the treatment of refractory pouchitis complicated by fistulae following ileal pouch-anal anastomosis for ulcerative colitis.

Sorbitol malabsorption and nonspecific abdominal symptoms in type II diabetes.

Some data suggest that sorbitol intake may be responsible for diarrhea in diabetic patients. One hundred thirteen hydrogen breath tests were performed in type II diabetics (72) and normal controls (41) after oral loads of sorbitol ranging from 2.5 to 20 g in iso-osmolar solutions to assess the role of malabsorption of this compound in the genesis of abdominal symptoms. The prevalence of sorbitol malabsorption and abdominal symptoms, peak (Cmax H2) and total (Ctot H2) hydrogen production, and mouth to cecum transit time (MCTT) did not differ in type II diabetics and controls. Malabsorption was observed more frequently with the highest doses of sorbitol (10% of patients at a dose of 2.5 g and approximately 75% at 20 g). Symptoms, usually consisting of mild discomfort and abdominal distension, were observed only after sorbitol loads of 10 and 20 g in 27.2% of the diabetics and in 36.3% of the controls. Diarrhea was present in three subjects (two diabetics and one control) only at a dose of 20 g. These data indicate that it is highly unlikely for sorbitol to play a role in inducing diabetes diarrhea. A moderate (up to 10 g) sorbitol intake is not contraindicated in type II diabetics.

Effect of rifaximin on intestinal bacterial overgrowth in Crohn's disease as assessed by the H2-Glucose Breath Test.

UNLABELLED: The occurrence of intestinal bacterial overgrowth in patients with Crohn's Disease (CD) has been described and antimicrobial treatment has been shown to be effective in reversing this condition. However, the mechanisms underlying the efficacy of antimicrobial therapy are still only partially known. The aim of the present study was to evaluate the effect of a non-absorbable antibiotic (rifaximin) in comparison to placebo on bacterial overgrowth in patients with CD. METHODS: Fourteen patients with inactive CD of the ileum and bacterial overgrowth, as assessed by the hydrogen breath test, were blindly allocated to receive rifaximin (1200 mg/day) or placebo t.i.d. for one week. A hydrogen breath test, and clinical and biochemical parameters were further performed 14 days and 30 days after starting treatment. RESULTS: After 14 days, the hydrogen breath test proved to be negative in seven out of seven patients treated with rifaximin (p < 0.05), and in two out of seven in the placebo group (p = ns). After 30 days, the hydrogen breath test was positive in all patients of the rifaximin and placebo group, respectively. No changes in the CDAI score were documented in any patients. CONCLUSIONS: Short-term administration of rifaximin is effective in the therapy of bacterial overgrowth in patients with inactive CD of the ileum, thus suggesting that the control of luminal bacterial growth could be useful in the management of these patients. However, since we observed a decline with time in this positive effect, further studies are needed to identify the most appropriate therapeutic strategies.

Effect of predominant methanogenic flora on the outcome of lactose breath test in irritable bowel syndrome patients.

BACKGROUND: The relationship between hydrogen and methane production is a possible confounding factor in the interpretation of H(2) breath tests (HBT), but is usually disregarded for the interpretation of HBT and, in most instances, only H(2) excretion is measured. The present study was designed to evaluate the effect of predominant fasting methane CH(4) or H(2) production on the outcome of lactose HBT, in a large, homogeneous series of adult patients with irritable bowel syndrome (IBS). PATIENTS AND METHODS: A lactose HBT was performed in 237 IBS patients with predominant fasting methane production (CH(4)>H(2)), recording the outcome of the test, amount of gas excreted and occurrence of clinical symptoms. Data were compared to those of 237 age- and sex-matched IBS patients with low fasting CH(4) excretion. RESULTS: The test was positive in 124 predominant CH(4) producers (52.3%) (PMP), as compared to 201 (84.8%) low methane producers (LMP) (P<0.0001). Peak hydrogen concentration and area under the curve of H(2) were significantly (P<0.001) lower, and the occurrence of symptoms during the test less frequent, in PMP vs LMP patients. During the test, CH(4) excretion doubled in 57/113 (50.4%) patients with negative HBT, and in 49/124 (39.5%) with positive HBT. CONCLUSIONS: Patients with predominant fasting methane production excrete less H(2) than LMP, after an oral load of lactose. The lower prevalence of severe lactose intolerance in PMP, as well as lower incidence of symptoms during the test, is, indeed, related to lower and slower H(2) excretion. The assumption that H(2) excretion is an effective means of quantifying the amount of malabsorbed carbohydrates is questionable in PMP. Methane-producing patients likely have a higher 'false negative' rate as compared to LMP after an oral load of lactose. Nonetheless, as symptoms are related to the amount of gas produced in the colon, HBT identifies patients with 'lactose intolerance', irrespective of the presence of lactose malabsorption, and helps in predicting the effect of lactose-restricted diet.

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.

Azathioprine treatment in inflammatory bowel disease patients: type and time of onset of side effects.

BACKGROUND: Azathioprine (AZA) and 6-mercaptopurine (6-MP), purine analogues, are the immunosuppressant drugs most frequently used for inducing and maintaining remission in inflammatory bowel disease (IBD). The occurrence of adverse effects is a major drawback in the use of these drugs, and short- and long-term toxicity represent a major limitation to their use. AIM: The present study investigated the prevalence, type and time of onset of AZA-related adverse events, in a cohort of IBD patients in a single referral Centre. PATIENTS AND METHODS: The records of consecutive IBD outpatients, referred to our Institution between 1987-2009, were retrospectively evaluated. RESULTS: We reviewed 2014 patients, in whom AZA was prescribed in 302 of them, 139 (46%) with ulcerative colitis (UC) and 163 (54%) with Crohn's disease (CD). Side-effects were complained by 98 (32.4%) out of 302 patients, 50 UC and 48 CD, (36% UC vs 29.4% CD, p = 0.26). In 20 (20.4%) patients, 11 UC and 9 CD, side-effects recovered after dosage reduction whilst in 78 (79.6%), 39 UC and 39 CD, the treatment was discontinued (dose-dependent side-effects in 42 patients and dose-independent in 36). Overall, side-effects were observed after a mean period of 14.5 ± 7.8 months (range 0.5-123) of AZA treatment. The majority (76%) of the dose-dependent adverse events were reported between 12-18 months after the beginning of treatment. CONCLUSIONS: The prevalence of side effects leading to withdrawal of AZA treatment, in our series of Italian patients, was higher respect to data reported in the literature (25.8%).

Patient with chest pain refractory to proton pump inhibitor: report of a case of eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is the most common form of gastrointestinal disorders associated with eosinophilia. Typically, an inappropriate accumulation of eosinophils is found in the esophageal mucosa. EoE can be well managed and treated with several options that include an elimination diet, drug therapy (oral and topical steroids) and esophageal dilatations. We herein, report a case of a 49-year-old male affected by EoE associated to chest pain, treated with proton pump inhibitor without clinical response. The patient suffered from long lasting postprandial fullness and gastroesophageal reflux disease-like symptoms. He had a history of episodic asthmatic attacks and allergic rhinitis but had not dysphagia or food impaction. The patient recovered completely after an adequate treatment.

Methodology and indications of H2-breath testing in gastrointestinal diseases: the Rome Consensus Conference.

BACKGROUND: Breath tests represent a valid and non-invasive diagnostic tool in many gastroenterological conditions. The rationale of hydrogen-breath tests is based on the concept that part of the gas produced by colonic bacterial fermentation diffuses into the blood and is excreted by breath, where it can be quantified easily. There are many differences in the methodology, and the tests are increasingly popular. AIM: The Rome Consensus Conference was convened to offer recommendations for clinical practice about the indications and methods of H2-breath testing in gastrointestinal diseases. METHODS: Experts were selected on the basis of a proven knowledge/expertise in H2-breath testing and divided into Working Groups (methodology; sugar malabsorption; small intestine bacterial overgrowth; oro-coecal transit time and other gas-related syndromes). They performed a systematic review of the literature, and then formulated statements on the basis of the scientific evidence, which were debated and voted by a multidisciplinary Jury. Recommendations were then modified on the basis of the decisions of the Jury by the members of the Expert Group. RESULTS AND CONCLUSIONS: The final statements, graded according to the level of evidence and strength of recommendation, are presented in this document; they identify the indications for the use of H2-breath testing in the clinical practice and methods to be used for performing the tests.