William D. Chey

American College of Gastroenterology Guideline on the Management of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) remains a prevalent, worldwide, chronic infection. Though the prevalence of this infection appears to be decreasing in many parts of the world, H. pylori remains an important factor linked to the development of peptic ulcer disease, gastric malignanc and dyspeptic symptoms. Whether to test for H. pylori in patients with functional dyspepsia, gastroesophageal reflux disease (GERD), patients taking nonsteroidal antiinflammatory drugs, with iron deficiency anemia, or who are at greater risk of developing gastric cancer remains controversial. H. pylori can be diagnosed by endoscopic or nonendoscopic methods. A variety of factors including the need for endoscopy, pretest probability of infection, local availability, and an understanding of the performance characteristics and cost of the individual tests influences choice of evaluation in a given patient. Testing to prove eradication should be performed in patients who receive treatment of H. pylori for peptic ulcer disease, individuals with persistent dyspeptic symptoms despite the test-and-treat strategy, those with H. pylori-associated MALT lymphoma, and individuals who have undergone resection of early gastric cancer. Recent studies suggest that eradication rates achieved by first-line treatment with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin have decreased to 70–85%, in part due to increasing clarithromycin resistance. Eradication rates may also be lower with 7 versus 14-day regimens. Bismuth-containing quadruple regimens for 7–14 days are another first-line treatment option. Sequential therapy for 10 days has shown promise in Europe but requires validation in North America. The most commonly used salvage regimen in patients with persistent H. pylori is bismuth quadruple therapy. Recent data suggest that a PPI, levofloxacin, and amoxicillin for 10 days is more effective and better tolerated than bismuth quadruple therapy for persistent H. pylori infection, though this needs to be validated in the United States.

Rifaximin Therapy for Patients with Irritable Bowel Syndrome without Constipation

BACKGROUND Evidence suggests that gut flora may play an important role in the pathophysiology of the irritable bowel syndrome (IBS). We evaluated rifaximin, a minimally absorbed antibiotic, as treatment for IBS. METHODS In two identically designed, phase 3, double-blind, placebo-controlled trials (TARGET 1 and TARGET 2), patients who had IBS without constipation were randomly assigned to either rifaximin at a dose of 550 mg or placebo, three times daily for 2 weeks, and were followed for an additional 10 weeks. The primary end point, the proportion of patients who had adequate relief of global IBS symptoms, and the key secondary end point, the proportion of patients who had adequate relief of IBS-related bloating, were assessed weekly. Adequate relief was defined as self-reported relief of symptoms for at least 2 of the first 4 weeks after treatment. Other secondary end points included the percentage of patients who had a response to treatment as assessed by daily self-ratings of global IBS symptoms and individual symptoms of bloating, abdominal pain, and stool consistency during the 4 weeks after treatment and during the entire 3 months of the study. RESULTS Significantly more patients in the rifaximin group than in the placebo group had adequate relief of global IBS symptoms during the first 4 weeks after treatment (40.8% vs. 31.2%, P=0.01, in TARGET 1; 40.6% vs. 32.2%, P=0.03, in TARGET 2; 40.7% vs. 31.7%, P<0.001, in the two studies combined). Similarly, more patients in the rifaximin group than in the placebo group had adequate relief of bloating (39.5% vs. 28.7%, P=0.005, in TARGET 1; 41.0% vs. 31.9%, P=0.02, in TARGET 2; 40.2% vs. 30.3%, P<0.001, in the two studies combined). In addition, significantly more patients in the rifaximin group had a response to treatment as assessed by daily ratings of IBS symptoms, bloating, abdominal pain, and stool consistency. The incidence of adverse events was similar in the two groups. CONCLUSIONS Among patients who had IBS without constipation, treatment with rifaximin for 2 weeks provided significant relief of IBS symptoms, bloating, abdominal pain, and loose or watery stools. (Funded by Salix Pharmaceuticals; ClinicalTrials.gov numbers, NCT00731679 and NCT00724126.).

An Evidence-Based Position Statement on the Management of Irritable Bowel Syndrome

IBS is characterized by abdominal discomfort associated with altered bowel function; structural and biochemical abnormalities are absent. e pathophysiology of IBS is multifactorial and of intense recent interest, largely because of the possibility of developing targeted therapies. As IBS is one of the most common disorders managed by gastroenterologists and primary care physicians, this monograph was developed to educate physicians about its epidemiology, diagnostic approach, and treatments. e American College of Gastroenterology (ACG) IBS Task Force updated the 2002 monograph because new evidence has emerged on the bene* t and risks of drugs used for IBS. Furthermore, new drugs also have been developed and the evidence for e+ cacy of these drugs needed to be assessed. To critically evaluate the rapidly expanding research about IBS, a series of systematic reviews were performed. Standard criteria for systematic reviews were met, including comprehensive literature searching, use of prespeci* ed study selection criteria, and use of a standardized and transparent process to extract and analyze data from studies. Evidence-based statements were developed from these data by the entire ACG IBS Task Force. Recommendations were graded using a formalized system that quanti* es the strength of evidence. Each recommendation was classi* ed as strong (grade 1) or weak (grade 2) and the strength of evidence classi* ed as strong (level A), moderate (level B), or weak (level C). Recommendations in this position statement may be crossreferenced with the supporting evidence in the accompanying article, “ An Evidenced Based Review on the Management of Irritable Bowel Syndrome ” .

The utility of probiotics in the treatment of irritable bowel syndrome: a systematic review.

OBJECTIVES:Irritable bowel syndrome (IBS) is a common disorder and available therapies have limited efficacy. Mucosal inflammation and alterations in gut microflora may contribute to the development of IBS symptoms, and researchers have hypothesized that probiotics might improve these symptoms. The aim of this study was to perform a systematic review of randomized controlled trials (RCTs) evaluating the efficacy, safety, and tolerability of probiotics in the treatment of IBS.METHODS:Comprehensive literature searches of multiple databases were performed. Study selection criteria were as follows: (i) RCTs, (ii) adults with IBS defined by Manning or Rome II criteria, (iii) single or combination probiotic vs. placebo, and (iv) improvement in IBS symptoms and/or decrease in frequency of adverse events reported. Data about study design and results were extracted in duplicate using standardized data extraction forms. Owing to variability in outcome measures, quantitative pooling of data was not feasible.RESULTS:A total of 16 RCTs met selection criteria. Of those, 11 studies showed suboptimal study design with inadequate blinding, inadequate trial length, inadequate sample size, and/or lack of intention-to-treat analysis. None of the studies provided quantifiable data about both tolerability and adverse events. Bifidobacterium infantis 35624 showed significant improvement in the composite score for abdominal pain/discomfort, bloating/distention, and/or bowel movement difficulty compared with placebo (P<0.05) in two appropriately designed studies. No other probiotic showed significant improvement in IBS symptoms in an appropriately designed study.CONCLUSIONS:B. infantis 35624 has shown efficacy for improvement of IBS symptoms. Most RCTs about the utility of probiotics in IBS have not used an appropriate study design and do not adequately report adverse events. Therefore, there is inadequate data to comment on the efficacy of other probiotics. Future probiotic studies should follow Rome II recommendations for appropriate design of an RCT.

ACG practice guidelines: Esophageal reflux testing

Investigations and technical advances have enhanced our understanding and management of gastroesophageal reflux disease. The recognition of the prevalence and importance of patients with endoscopy-negative reflux disease as well as those refractory to proton pump inhibitor therapy have led to an increasing need for objective tests of esophageal reflux. Guidelines for esophageal reflux testing are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Issues regarding the utilization of conventional, catheter-based pH monitoring are discussed. Improvements in the interpretation of esophageal pH recordings through the use of symptom-reflux association analyses as well as limitations gleaned from recent studies are reviewed. The clinical utility of pH recordings in the proximal esophagus and stomach is examined. Newly introduced techniques of duodenogastroesophageal reflux, wireless pH capsule monitoring and esophageal impedance testing are assessed and put into the context of traditional methodology. Finally, recommendations on the clinical applications of esophageal reflux testing are presented.

Clinical trial: lubiprostone in patients with constipation-associated irritable bowel syndrome – results of two randomized, placebo-controlled studies

Background  Effective treatments for irritable bowel syndrome with constipation (IBS‐C) are lacking.

Levofloxacin-Based Triple Therapy versus Bismuth-Based Quadruple Therapy for Persistent Helicobacter pylori Infection: A Meta-Analysis

BACKGROUND:Levofloxacin-based triple therapy has been suggested as an alternative salvage therapy to bismuth-based quadruple therapy for persistent Helicobacter pylori (H. pylori) infection.METHODS:A search of PUBMED, EMBASE, EBM Review databases and abstracts from recent Digestive Disease Week, United European Gastroenterology Week, and European Helicobacter Study Group conferences was performed. Randomized controlled trials (RCTs) comparing levofloxacin-based triple salvage therapy (levofloxacin + amoxicillin + PPI) to bismuth-based quadruple salvage therapy (bismuth + tetracycline + metronidazole + PPI) were selected for meta-analysis. Additionally, all prospective trials evaluating this levofloxacin-based triple therapy as salvage therapy were pooled to analyze optimal levofloxacin treatment duration and dosing. All selected trials confirmed prior treatment failure and post-salvage treatment eradication.RESULTS:Four RCTs compared a 10-day regimen of levofloxacin-based triple therapy to 7-day bismuth-based quadruple therapy (n = 391 patients). Levofloxacin-based triple therapy was superior to quadruple therapy (RR = 1.41 [95% CI: 1.25–1.59]). Levofloxacin-based triple therapy was better tolerated than quadruple therapy with a lower incidence of side effects (RR = 0.51 [95% CI: 0.34–0.75]) and side effects prompting discontinuation of therapy (RR = 0.30 [95% CI: 0.10–0.89]). Eleven trials (n = 547 patients) evaluating levofloxacin-based triple therapy demonstrated higher eradication rates with 10-day versus 7-day regimen (87%[95% CI: 82%-92%]vs 68%[95% CI: 62%-74%]) yet eight trials (n = 477 patients) demonstrated no difference with 500 mg daily versus 250 mg b.i.d. dosing of levofloxacin (81%[95% CI: 78%-89%]vs 84%[95% CI: 66%-97%]).CONCLUSIONS:A 10-day course levofloxacin triple therapy is more effective and better tolerated than 7-day bismuth-based quadruple therapy in the treatment of persistent H. pylori infection.

Linaclotide for Irritable Bowel Syndrome With Constipation: A 26-Week, Randomized, Double-blind, Placebo-Controlled Trial to Evaluate Efficacy and Safety

OBJECTIVES:Linaclotide is a minimally absorbed peptide guanylate cyclase-C agonist. The objective of this trial was to determine the efficacy and safety of linaclotide treatment in patients with irritable bowel syndrome with constipation (IBS-C) over 26 weeks.METHODS:This phase 3, double-blind, parallel-group, placebo-controlled trial randomized IBS-C patients to placebo or 290 μg of oral linaclotide once daily for a 26-week treatment period. The primary and the secondary efficacy assessments were evaluated over the first 12 weeks of treatment. Primary end points included the Food and Drug Administrations (FDAs) end point for IBS-C (responder: a patient who reported (i) improvement of ≥30% from baseline in average daily worst abdominal pain score and (ii) increase of ≥1 complete spontaneous bowel movement (CSBM) from baseline, both in the same week for ≥6/12 weeks) and three other primary end points, based on improvements in abdominal pain and CSBMs for 9/12 weeks. Adverse events (AEs) were monitored.RESULTS:In all, 804 patients (mean age=44 years, female=90%, white=78%) were evaluated; 33.7% of linaclotide-treated patients were FDA end point responders, vs. 13.9% of placebo-treated patients (P<0.0001) (number needed to treat=5.1, 95% confidence interval (CI): 3.9, 7.1). The pain responder criterion of the FDA end point was met by 48.9% of linaclotide-treated patients vs. 34.5% of placebo-treated patients (number needed to treat=7.0, 95% CI: 4.7, 13.1), and the CSBM responder criterion was met by 47.6% of linaclotide-treated patients, vs. 22.6% of placebo patients (number needed to treat=4.0, 95% CI: 3.2, 5.4). Remaining primary end points (P<0.0001) and all secondary end points (P<0.001), including abdominal pain, abdominal bloating, and bowel symptoms (SBM and CSBM rates, Bristol Stool Form Scale (BSFS) score, and straining), were also statistically significantly improved with linaclotide vs. placebo. Statistically significant differences from placebo were observed for responder and continuous end points over 26 weeks of treatment. AE incidence was similar between treatment groups, except for diarrhea, which caused discontinuation in 4.5% of linaclotide patients vs. 0.2% of placebo patients.CONCLUSIONS:Linaclotide 290 μg once daily significantly improved abdominal and bowel symptoms associated with IBS-C over 26 weeks of treatment.

Irritable Bowel Syndrome: A Clinical Review

IMPORTANCE Irritable bowel syndrome (IBS) affects 7% to 21% of the general population. It is a chronic condition that can substantially reduce quality of life and work productivity. OBJECTIVES To summarize the existing evidence on epidemiology, pathophysiology, and diagnosis of IBS and to provide practical treatment recommendations for generalists and specialists according to the best available evidence. EVIDENCE REVIEW A search of Ovid (MEDLINE) and Cochrane Database of Systematic Reviews was performed for literature from 2000 to December 2014 for the terms pathophysiology, etiology, pathogenesis, diagnosis, irritable bowel syndrome, and IBS. The range was expanded from 1946 to December 2014 for IBS, irritable bowel syndrome, diet, treatment, and therapy. FINDINGS The database search yielded 1303 articles, of which 139 were selected for inclusion. IBS is not a single disease but rather a symptom cluster resulting from diverse pathologies. Factors important to the development of IBS include alterations in the gut microbiome, intestinal permeability, gut immune function, motility, visceral sensation, brain-gut interactions, and psychosocial status. The diagnosis of IBS relies on symptom-based criteria, exclusion of concerning features (symptom onset after age 50 years, unexplained weight loss, family history of selected organic gastrointestinal diseases, evidence of gastrointestinal blood loss, and unexplained iron-deficiency anemia), and the performance of selected tests (complete blood cell count, C-reactive protein or fecal calprotectin, serologic testing for celiac disease, and age-appropriate colorectal cancer screening) to exclude organic diseases that can mimic IBS. Determining the predominant symptom (IBS with diarrhea, IBS with constipation, or mixed IBS) plays an important role in selection of diagnostic tests and treatments. Various dietary, lifestyle, medical, and behavioral interventions have proven effective in randomized clinical trials. CONCLUSIONS AND RELEVANCE The diagnosis of IBS relies on the identification of characteristic symptoms and the exclusion of other organic diseases. Management of patients with IBS is optimized by an individualized, holistic approach that embraces dietary, lifestyle, medical, and behavioral interventions.

Comparison of gastric emptying of a nondigestible capsule to a radio-labelled meal in healthy and gastroparetic subjects

Background  Gastric emptying scintigraphy (GES) using a radio‐labelled meal is used to measure gastric emptying. A nondigestible capsule, SmartPill, records luminal pH, temperature, and pressure during gastrointestinal transit providing a measure of gastric emptying time (GET).