# IMarch 2011 Issue of Gastroenterology Clinics of North America contains state-of-the-art clinical reviews on IBS



## Jeffrey Roberts (Apr 15, 1987)

Irritable Bowel Syndrome: Gastroenterology Clinics of North America Volume 40, Issue 1, Pages 1-264 (March 2011)William D. Chey, MD, AGAF, Guest Editor"It is with great pride that I introduce this issue of Gastroenterology Clinics of North America, which presents state-of-the-art clinical reviews on Irritable Bowel Syndrome or IBS. It has been more than 5 years since Gastroenterology Clinics last reviewed this prevalent but vexing disorder. In that period of time, much has been learned about a variety of topics relevant to IBS. A search of the term "irritable bowel syndrome" on ISI Web of Knowledge, limited to GI specialty journals, yields over 1,800 published articles over the past 5 years. In the following pages, the world's leading experts summarize and place into clinical perspective much of the most important emerging evidence on IBS."Full Issue >>Articles in Issue:Epidemiology of IBS Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder. Because not everyone needs to seek care, population-based studies are needed to truly understand the epidemiology of IBS. About 10% of the population has IBS at any one time and about 200 people per 100,000 will receive an initial diagnosis of IBS over the course of a year. IBS patients are more frequently younger in age, and a female predominance has been observed in Western countries and tertiary care settings. IBS patients commonly report overlapping upper GI, as well as a variety of non-GI, complaints. Rok Seon Choung, G. Richard Locke pages 1-10 The Effect of Irritable Bowel Syndrome on Health-Related Quality of Life and Health Care Expenditures Irritable bowel syndrome (IBS) is a highly prevalent condition with a large health economic burden of illness marked by impaired health-related quality of life (HRQOL), diminished work productivity, and high expenditures. Clinicians should routinely screen for diminished HRQOL by performing a balanced biopsychosocial history rather than focusing just on bowel symptoms. HRQOL decrements should be acknowledged and addressed when making treatment decisions. Nikhil Agarwal, Brennan M.R. Spiegel pages 11-19 Traditional Thoughts on the Pathophysiology of Irritable Bowel Syndrome The pathogenesis of symptoms in irritable bowel syndrome (IBS) is multifactorial and varies from patient to patient. Disturbances of motor function in the small intestine and colon and smooth-muscle dysfunction in other gut and extraintestinal regions are prominent. Abnormalities of sensory function in visceral and somatic structures are detected in most patients with IBS, which may relate to peripheral sensitization or altered central nervous system processing of afferent information. Contributions from psychosocial disturbances are observed in patients from tertiary centers and primary practice. Proof of causation of symptom genesis for most of these factors is limited. William L. Hasler pages 21-43 The Role of Genetics in IBS Irritable bowel syndrome (IBS) is a common disorder that has been shown to aggregate in families and to affect multiple generations, but not in a manner consistent with a major Mendelian effect. Relatives of an individual with IBS are 2 to 3 times as likely to have IBS, with both genders being affected. To date, more than 100 genetic variants in more than 60 genes from various pathways have been studied in a number of candidate gene studies, with several positive associations reported. These findings suggest that there may be distinct, as well as shared, molecular underpinnings for IBS and its subtypes. Yuri A. Saito pages 45-67 Inflammation and Microflora Irritable bowel syndrome (IBS) is the most common gastrointestinal condition, affecting 10% to 20% of adults in developed countries. Over the last few years, growing evidence has supported a new hypothesis for IBS based on alterations in intestinal bacterial composition. This article reviews the evidence for a bacterial concept in IBS and begins to formulate a hypothesis of how these bacterial systems could integrate in a new pathophysiologic mechanism in the development of IBS. Data suggesting an interaction between this gut flora and inflammation in the context of IBS is also presented. Mark Pimentel, Christopher Chang pages 69-85 Symptom-Based Diagnostic Criteria for Irritable Bowel Syndrome: the More Things Change, the More They Stay the Same Medical students are taught that 90% of all diagnoses are made through careful assessment of the patients' symptoms. Clinicians now rely heavily on techniques such as endoscopy or radiology before making a definitive diagnosis of organic disease. Most gastroenterologists would require endoscopic confirmation before labeling a patient as having peptic ulcer disease and would make a diagnosis of Crohn disease based on small bowel radiology or colonoscopy. However, the most common causes of symptoms of the gastrointestinal tract are functional. It is important that clinicians obtain a thorough history so that the disorder of the patient can be accurately defined. Paul Moayyedi, Alexander C. Ford pages 87-103 )	The Role of Diagnostic Testing in Irritable Bowel Syndrome This article discusses the diagnostic criteria and processes applicable to irritable bowel syndrome (IBS). The authors describe the various diagnostic criteria with a focus on the Rome criteria for IBS and the judicious application of historical information such as alarm features and the yield of various diagnostic modalities such as blood, stool, breath, and endoscopic tests. David L. Furman, Brooks D. Cash pages 105-119 Potential Biomarkers A "biomarker" (biological marker) is an indicator of a bodily function that can be objectively measured. A wide range of possible biomarkers for IBS have been considered but at present only gut transit measured using radio-isotope markers meet the criteria of reproducibility and availability. While barostat studies perform reasonably in expert centers, to do them reproducibly requires considerable effort and standardization. This makes them unsuitable for widespread use. However radio-isotope tests are expensive and of limited availability so the search for other more convenient markers including blood and stool tests is still an important goal for the future. Robin C. Spiller pages 121-139 Food: The Forgotten Factor in the Irritable Bowel Syndrome After years of inattention, there is a growing body of evidence to suggest that dietary constituents at least exacerbate symptoms and perhaps contribute to the pathogenesis of the irritable bowel syndrome (IBS). Although patients with IBS self-report food allergies more often than the general population, the evidence suggests that true food allergies are relatively uncommon. Less clearly defined food intolerances may be an important contributor to symptoms in IBS patients. This article reviews the literature supporting a causal link between food and the symptoms of IBS as well as the evidence supporting dietary interventions as a means of managing IBS symptoms. Shanti Eswaran, Jan Tack, William D. Chey pages 141-162 Peripherally Acting Therapies for the Treatment of Irritable Bowel Syndrome Gut-acting therapies are common therapies for irritable bowel syndrome (IBS). Most of these peripheral acting agents are primarily targeted at individual symptoms. The evidence supporting the use of these agents in IBS is largely anecdotal. Serotonergic agents and the chloride channel activator lubiprostone have shown efficacy in treating symptoms of IBS. The clinical evidence supporting the use of these agents is based on data from high-quality clinical trials. The use of serotonergic agents for IBS in the United States is limited to the 5-hydroxytryptamine-3 antagonist alosetron in the treatment of women with severe IBS with diarrhea refractory to traditional therapy. Richard J. Saad pages 163-182 Centrally Acting Therapies for Irritable Bowel Syndrome Irritable bowel syndrome (IBS) and other functional gastrointestinal (GI) disorders typically defy traditional diagnostic methods based on structural abnormalities, and has led to the emergence of the discipline of neurogastroenterology or the study of the "brain-gut axis," which is based on dysregulation of neuroenteric pathways as a key pathophysiological feature of IBS. Centrally acting treatments can influence these pathways and improve the clinical manifestations of pain and bowel dysfunction associated with this disorder. To successfully implement these treatment strategies, it is important to recognize their dual effects on brain and gut, understanding the nature and severity of the GI symptoms and their psychosocial concomitants, and applying them within the context of the patient's understanding of their value. Madhusudan Grover, Douglas A. Drossman pages 183-206 Therapies Aimed at the Gut Microbiota and Inflammation: Antibiotics, Prebiotics, Probiotics, Synbiotics, Anti-inflammatory Therapies Several recent observations have raised the possibility that disturbances in the gut microbiota and/or a low-grade inflammatory state may contribute to symptomatology and the etiology of irritable bowel syndrome (IBS). Consequent on these hypotheses, several therapeutic categories have found their way into the armamentarium of those who care for IBS sufferers. These agents include probiotics, prebiotics, antibiotics, and anti-inflammatory agents. Eamonn M.M. Quigley pages 207-222 Emerging Pharmacological Therapies for the Irritable Bowel Syndrome The irritable bowel syndrome (IBS) is a symptom-based disorder defined by the presence of abdominal pain and altered bowel habits. Clinical presentations of IBS are diverse, with some patients reporting diarrhea, some constipation, and others a mixture of both. Like the varied clinical phenotypes, the pathogenesis of IBS is also diverse. IBS is not a single disease entity, but rather likely consists of several different disease states. This fact has important implications for the choices and efficacy of IBS treatment. This article reviews the IBS drugs that have reached phase II or III clinical trials. Monthira Maneerattanaporn, Lin Chang, William D. Chey pages 223-243 Complementary and Alternative Medicine for the Irritable Bowel Syndrome Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder, characterized by chronic or recurrent abdominal pain and bloating. Complementary and alternative medicine (CAM) is a diverse group of medical treatments that are not commonly considered to be a part of conventional medicine yet frequently used together with conventional medicine. CAM is widely used, particularly for chronic medical conditions that are difficult to treat. Because only a limited number of treatments are available for IBS, many patients choose CAM. This article reviews current evidence supporting the use of CAM in IBS, with a focus on prebiotics, acupuncture, and herbal medicines. Suma Magge, Anthony Lembo pages 245-253 Copyright © 2011 Elsevier, Inc. All rights reserved.The contents of this issue is intended for health professionals.


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