Feature

Environmental Risk Factors for Inflammatory Bowel Disease

Ashwin N. Ananthakrishnan, MD, MPH

Crohn’s disease (CD) and ulcerative colitis (UC) are chronic immunologically mediated diseases that often have a relapsing-remitting course in young persons. Genetic-risk polymorphisms explain less than one third of the heritability of disease. Epidemiologic and laboratory data suggest that environmental factors play a significant role in influencing the risk and natural history of disease. Smoking is the most widely and consistently described risk factor. It, however, increases the risk of CD while conferring protection against UC. The gut microbiome is a key component in the development of inflammatory bowel disease (IBD). Several external factors potentially exert an effect by influencing the composition of the gut microbiome or disrupting the intestinal barrier. These external influences include the use of antibiotics or nonsteroidal anti-inflammatory drugs and the presence of enteric infections. Data on diet have been inconsistent, but high fiber intake, particularly of soluble fiber, appears to protect against CD, whereas protein intake may increase disease risk. Vitamin D may also play an important protective role, particularly in patients with CD. Neurobehavioral factors, such as stress and depression, also influence the risk of IBD. Systematic and rigorous studies of environmental exposures in the management of IBD are needed. In particular, studies of whether environmental factors can be modified to reduce the likelihood of relapse or improve patient outcomes would be valuable.

Letter From the Editor

Letter from the Editor

Gary R. Lichtenstein, MD, AGAF, FACP, FACG

Last month, the United States Department of Agriculture (USDA) unveiled the federal government’s new food icon, MyPlate, a tool designed to help Americans make healthier food […]

Feature

New Developments in Traveler’s Diarrhea

Javier de la Cabada Bauche, MD; Herbert L. DuPont, MD

Abstract: Traveler’s diarrhea (TD) is a crucial area for research, as it affects millions of tourists each year and creates a large economic burden. More than 60% of TD cases are caused by a variety of bacterial enteropathogens: diarrhea-producing Escherichia coli, Shigella, Campylobacter, Salmonella, Aeromonas, Plesiomonas, and noncholera Vibrios. Noroviruses are also an important cause of morbidity among travelers. Recent studies have identified host genetic risk factors associated with susceptibility to pathogen-specific TD. Prevention strategies should be emphasized, as all individuals with TD experience approximately 24 hours of disability and 5–10% experience chronic functional bowel disease. Poorly absorbed rifaximin provides protection for trips lasting 2 weeks or less. TD vaccines are also currently in development. All individuals planning trips to developing regions should be armed with 1 of the 3 agents that have shown efficacy for self-treatment of TD: ciprofloxacin (or levofloxacin), rifaximin, or azithromycin, depending upon the location of the trip. Although global epidemiologic changes in etiologic agents as well as antibiotic resistance patterns have been better understood recently, changes should be expected during the next decade due to new prevention and treatment approaches.

IBS

Highlights From the New ACG Clinical Guideline for Gastroparesis

G&H  Why did the American College of Gastroenterology recently update its clinical guideline on gastroparesis, and what is the main focus of the updated guideline? MC  […]

IBD

Overview of Total Parenteral Nutrition in Patients With Inflammatory Bowel Disease

G&H  How often does malnutrition occur in the setting of inflammatory bowel disease?  HB  Malnutrition is very prevalent among patients with inflammatory bowel disease (IBD). It […]

Gastroenterology

Review of Abdominal Migraine in Children 

Demiana J. Azmy and Cary M. Qualia, MD 

  Abstract: Abdominal migraine is a type of functional abdominal pain disorder that affects 0.2% to 4.1% of children. It consists of paroxysmal, recurrent, and acute […]

Gastro-Hep News

Gastro-Hep News

Samantha Alleman

US Food and Drug Administration Approves Marketing of Medical Device for Reduction of IBS-Associated Pain in Adolescents On June 7, 2019, the US Food and Drug […]

GERD

An Overview of Dietary Therapies for the Treatment of Eosinophilic Esophagitis

Ikuo Hirano, MD

  G&H  What is the connection between food and eosinophilic esophagitis? IH  The connection between food and eosinophilic esophagitis (EoE) was first described in a 1995 […]

Advances in Endoscopy

Training Model for Endoscopic Ultrasound–Guided Fine-Needle Aspiration of Lymph Nodes

Annette Fritscher-Ravens, MD

Annette Fritscher-Ravens, MD  Professor of Gastroenterology Experimental Endoscopy Unit Internal Medicine I University Hospital Schleswig-Holstein Campus Kiel Kiel, Germany G&H What training models are currently available for […]

Feature

Low-FODMAP Diet for Treatment of Irritable Bowel Syndrome

Suma Magge, MD, and Anthony Lembo, MD

Functional bowel disorders, including irritable bowel syndrome (IBS), are common disorders that have a significant impact on patients’ quality of life. These disorders present major challenges to healthcare providers, as few effective medical therapies are currently available. Recently, there has been increasing interest in dietary therapies for IBS, particularly a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). Since ingestion of FODMAPs increases the delivery of readily fermentable substrates and water to the distal small intestine and colon—which results in luminal distention and gas—the reduction of FODMAPs in a patient’s diet may improve functional gastrointestinal symptoms. This paper will review the pathophysiology of IBS and the role of FODMAPs for the treatment of this condition.