European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus.

INTRODUCTION: Measurement of breath hydrogen (H2 ) and methane (CH4 ) excretion after ingestion of test-carbohydrates is used for different diagnostic purposes. There is a lack of standardization among centers performing these tests and this, together with recent technical developments and evidence from clinical studies, highlight the need for a European guideline. METHODS: This consensus-based clinical practice guideline defines the clinical indications, performance, and interpretation of H2 -CH4 -breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 44 experts from 18 European countries. Eighty eight statements and recommendations were drafted based on a review of the literature. Consensus (≥80% agreement) was reached for 82. Quality of evidence was evaluated using validated criteria. RESULTS: The guideline incorporates new insights into the role of symptom assessment to diagnose carbohydrate (e.g., lactose) intolerances and recommends that breath tests for carbohydrate malabsorption require additional validated concurrent symptom evaluation to establish carbohydrate intolerance. Regarding the use of breath tests for the evaluation of oro-cecal transit time and suspected small bowel bacterial overgrowth, this guideline highlights confounding factors associated with the interpretation of H2 -CH4 -breath tests in these indications and recommends approaches to mitigate these issues. CONCLUSION: This clinical practice guideline should facilitate pan-European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, it identifies areas of future research needs to clarify diagnostic and therapeutic approaches.

Gastric administration of garlic powder containing the trpa1- agonist allicin induces specific epigastric symptoms and gastric relaxation in healthy subjects.

BACKGROUND: TRPA1 is an excitatory ion channel and is involved in sensory processes including thermal nociception and inflammatory pain. The allicin in garlic is a strong activator of the TRPA1 channel. AIM: To evaluate the effect of intragastric garlic powder containing allicin on perception, gastric tone, and mechanosensitivity. METHODS: An infusion-barostat balloon assembly was used for infusion of test solutions, for distension, and to measure proximal gastric compliance and tone. After an initial open label dose finding with 1 g, 2 g, 3.75 g, and 7.5 g commercially available garlic powder, a bolus of 2 g garlic powder (11 mg allicin)/60 mL H2 O was considered to induce moderate but constant sensation and was used hereafter in a placebo-controlled, single-dose, double-blind, randomized study in 7 volunteers to evaluate gastric sensation, tone, and mechanosensitivity. KEY RESULTS: Bolus injection of garlic caused immediate epigastric symptoms, mean aggregate symptom scores (AUC in 15 minutes) were 106 ± 49 vs. 35 ± 30 after placebo (P = 0.01). Garlic induced significant epigastric pressure, stinging, and warmth (P < 0.01 vs. placebo), while intensity of cramps, satiety, nausea, and pain was not significantly different to placebo (P > 0.05). Garlic induced an immediate, short lived fundic relaxation (balloon volume 627 ± 349 mL vs. -145 ± 120 mL; P < 0.02). No effect of allicin on proximal gastric mechanosensitivity and compliance was observed (NS). CONCLUSION AND INFERENCES: Garlic containing allicin induces immediate epigastric symptoms of pressure, stinging, and warmth and induces fundic relaxation but does not influence mechanosensitivity or compliance. TRPA1 is a receptor that is involved in gastric sensation and motility.

Identification of Individuals with Functional Dyspepsia With a Simple, Minimally Invasive Test: A Single Center Cohort Study of the Oral Capsaicin Test.

OBJECTIVES: The diagnosis of functional dyspepsia (FD) is challenging due to the lack of reliable biological markers to support the diagnosis. We assessed the relevance of a previously validated simple test for chemical hypersensitivity in the setting of a gastrointestinal outpatient department. METHODS: A total of 224 outpatients who were referred for evaluation of gastrointestinal symptoms in the absence of alarm symptoms swallowed a capsule containing 0.75 mg capsaicin. Severity of symptoms before and after capsule ingestion was assessed by a graded questionnaire and the difference in aggregate symptom scores (delta) was calculated. RESULTS: Sensitivity of the test was between 0.51-0.59, specificity was 0.84-0.89 and positive predictive value for the diagnosis of FD 70-71%. FD patients had significantly higher median delta symptom scores (10.0; 25% quartile: 3.0; 75% quartile: 16.0) as compared to inflammatory bowel disease (2.5; 1.0/8.5)(P=0.003), peptic ulcer disease (0.0; -1.5/4.5) (P<0.001), irritable bowel syndrome (3.0;0.5/8.5)(P=0.001), and patients classified with "other disease" (2.5;0.0/5.0)(P<0.001). Patients with gastroesophageal reflux disease had significantly lower symptom scores if FD was not concomitantly diagnosed (2.0; 0.0/6.0) than if FD was present (10.0; 4.0/15.0). CONCLUSIONS: Hypersensitivity for capsaicin discriminates functional dyspepsia from patients with other GI disorders. The capsaicin test is a simple and non invasive method to detect a large subgroup of functional dyspepsia with chemical hypersensitivity. These findings might open new diagnostic options in functional dyspepsia and possibly new therapeutic options by targeting the specific capsaicin receptor TRPV1.

Lack of an Effect of Gastric Capsaicin on the Rectal Component of the Gastrocolonic Response.

Luminal capsaicin induces local and distant reflexes in the upper gastrointestinal tract and stimulates lower gastrointestinal symptoms in susceptible persons. We aimed to evaluate the effect of gastric capsaicin on rectal motor function and sensation. METHODS: Eighteen healthy volunteers participated twice, at least 1 week apart, in this double-blind, placebo-controlled crossover study. Participants swallowed a gastric tube for capsaicin or saline infusion. A barostat tube was placed in the rectum to measure rectal tone before and during gastric capsaicin (40 µg/ml, 2.5 ml/min) or placebo infusion and to conduct distension experiments before and after gastric infusions. Gastric infusions were terminated after 60 min or when epigastric discomfort occurred. Differences in rectal tone, compliance, and sensitivity between gastric placebo and gastric capsaicin were determined. RESULTS: On both study days, basal rectal volumes, compliance, and sensitivity parameters were comparable (NS) before gastric infusions. Gastric capsaicin infusion induced epigastric discomfort that necessitated termination of infusion after 29.6 ± 12.3 min (saline: 54.7 ± 8.9 min; p < 0.01). Rectal tone, aggregate perception scores, and rectal compliance did not differ between placebo and capsaicin trials (p > 0.05). Rectal tone increased significantly only when capsaicin induced epigastric discomfort (p < 0.05). The reproducibility of the barostat trial was acceptable with significant correlations of volumes, pressures (< 0.05; r 2 from 0.41 to 0.55), rectal compliance (p < 0.01; r 2 = 0.44), and aggregate perception scores (p values all < 0.05; r 2 from 0.44 to 0.0.65) between the two barostat trials. CONCLUSION: Gastric perfusion with capsaicin does not directly influence rectal physiology through a reflex arc.

Gastric phenotype in children with Helicobacter pylori infection undergoing upper endoscopy.

INTRODUCTION: Helicobacter pylori is a definite risk factor for the development of gastric cancer, especially in the context of corpus-predominant gastritis. The infection is usually acquired in early childhood, implying lifelong exposure to this carcinogen if untreated. Our objective was to analyze the prevalence of H. pylori induced corpus-predominant gastritis in children. MATERIAL AND METHODS: We analyzed the results of 265 esophagogastroduodenoscopies (EGD) in children performed between February 2006 and August 2008; 34 endoscopies were excluded (24 with follow-up investigations, 5 with incomplete data, 5 adults). H. pylori gastritis was defined by the presence of H. pylori in histology or by a positive rapid urease test. Grade of inflammation was rated according to the updated Sydney Scoring System. Gastritis was classified as corpus-predominant when the degree of chronic inflammation was higher in the corpus than in the antrum and vice versa for antrum-predominant gastritis. RESULTS: Two hundred thirty-one patients (128 female; mean age ± SEM: 10.5 ± 3.5 years) were analyzed. Eighty-four (36%) were H. pylori positive, 147 (64%) patients were negative for H. pylori. In H. pylori positive patients, 39 (46%) patients had pangastritis (one patient with mucosal atrophy, which is regarded as precancerous lesion), 42 (50%) had antrum-predominant gastritis and 3 (4%) had corpus-predominant gastritis. One female patient (15.6 years old) with severe (grade 3) pangastritis had focal mucosal atrophy in both antrum and corpus, but no patient had intestinal metaplasia. CONCLUSIONS: Corpus-predominant gastritis develops in H. pylori infected children, while mucosal atrophy and intestinal metaplasia develop later in the course of the infection.

Correlation of dose-volume parameters, endoscopic and clinical rectal side effects in cervix cancer patients treated with definitive radiotherapy including MRI-based brachytherapy.

PURPOSE: Correlation of dosimetric parameters for MRI-based 3D treatment planning with rectoscopic findings and clinical rectal side effects. METHODS AND MATERIALS: Rectosigmoidoscopy and rectal morbidity assessment were performed on 35 cervical cancer patients treated with external beam radiotherapy (EBRT) and HDR-intracavitary brachytherapy (ICB). The total doses, normalised to 2 Gy fractions (EQD2, alpha/beta=3 Gy), in 0.1, 1.0 and 2.0 cm(3) (D(0.1 cc), D(1 cc), D(2 cc)) of rectum were determined by summation of EBRT and ICB plans. Correlation analysis between clinical symptoms (LENT/SOMA) and rectoscopic changes (Vienna Rectoscopy Score, VRS) was performed. For dose-response analyses, the logit model was applied. RESULTS: Mean follow-up was 18 months. LENT/SOMA score was 1 in 4 patients, 2 in 8 patients, 4 in 1 patient. Telangiectasia was found in 26 patients (74%), five of them had ulceration corresponding to the 0.1 cm(3) volume (anterior wall). Mean values D(0.1 cc), D(1 cc), and D(2 cc) were 81+/-13, 70+/-9 and 66+/-8 Gy, respectively. The ED50 values for VRS > or = 3 and for LENT/SOMA > or = 2 significantly increased with decreasing volumes. D(2 cc) was higher in patients with VRS > or = 3 compared to VRS<3 (72+/-6 vs 62+/-7 Gy; p<0.001) and in symptomatic vs asymptomatic patients (72+/-6 vs 63+/-8 Gy; p<0.001). VRS correlated with the LENT/SOMA score. CONCLUSIONS: Rectosigmoidoscopy is sensitive in detecting mucosal changes, independent of clinical symptoms. The localization of these changes corresponds to the high dose volumes as defined by imaging. The development of mucosal and clinical changes in the rectum follows a clear dose-effect and volume-effect. DVH parameters could be established.