In the United States, colorectal cancer (CRC) is the third most common cancer diagnosed among men and women and the second leading cause of death from cancer. CRC largely can be prevented by the detection and removal of adenomatous polyps, and survival is significantly better when CRC is diagnosed while still localized. In 2006 to 2007, the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology came together to develop consensus guidelines for the detection of adenomatous polyps and CRC in asymptomatic average-risk adults. In this update of each organization's guidelines, screening tests are grouped into those that primarily detect cancer early and those that can detect cancer early and also can detect adenomatous polyps, thus providing a greater potential for prevention through polypectomy. When possible, clinicians should make patients aware of the full range of screening options, but at a minimum they should be prepared to offer patients a choice between a screening test that primarily is effective at early cancer detection and a screening test that is effective at both early cancer detection and cancer prevention through the detection and removal of polyps. It is the strong opinion of these 3 organizations that colon cancer prevention should be the primary goal of screening.

Studies using mice have yielded significant amounts of information regarding signaling pathways, such as Wnt, bone morphogenic protein, PtdIns(3,4,5) kinase, and Notch, involved in intestinal development and homeostasis, including stem cell regulation and lineage specification and maturation. However, attempts to model signals definitively that control intestinal stem cells have been difficult because of a long-standing and recently reenergized debate surrounding their location. Although crypt-based columnar cells have been recently shown to display self-renewal and multipotential capacity, a large body of evidence supports long-term label-retaining cells, located on average at the +4 position just above the Paneth cells, as putative stem cells. Herein, we propose that both these cell types represent true intestinal stem cells maintained in different states (quiescent vs actively cycling), presumably via interactions with different microenvironments. Finally, we review current findings regarding the roles of Wnt, bone morphogenic protein, PtdIns(3,4,5) kinase, and Notch pathways within the intestine.

Acute pancreatitis is a common complication of endoscopic retrograde cholangiopancreatography and benefit of pharmacological treatment is unclear. Although prophylactic use of corticosteroid for reduction of pancreatic injury after ERCP has been evaluated, discrepancy about beneficial effect of corticosteroid on pancreatic injury still exists. The aim of current study is to evaluate effectiveness and safety of corticosteroid in prophylaxis of post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP).

We aimed to review the literature regarding the epidemiology of constipation in Europe and Oceania and the associated prevalence/risk factors.

The predominantly anaerobic microbiota of the distal ileum and colon contain an extraordinarily complex variety of metabolically active bacteria and fungi that intimately interact with the host's epithelial cells and mucosal immune system. Crohn's disease, ulcerative colitis, and pouchitis are the result of continuous microbial antigenic stimulation of pathogenic immune responses as a consequence of host genetic defects in mucosal barrier function, innate bacterial killing, or immunoregulation. Altered microbial composition and function in inflammatory bowel diseases result in increased immune stimulation, epithelial dysfunction, or enhanced mucosal permeability. Although traditional pathogens probably are not responsible for these disorders, increased virulence of commensal bacterial species, particularly Escherichia coli, enhance their mucosal attachment, invasion, and intracellular persistence, thereby stimulating pathogenic immune responses. Host genetic polymorphisms most likely interact with functional bacterial changes to stimulate aggressive immune responses that lead to chronic tissue injury. Identification of these host and microbial alterations in individual patients should lead to selective targeted interventions that correct underlying abnormalities and induce sustained and predictable therapeutic responses.

Treatment of chronic hepatitis B virus (HBV) infection is aimed at suppressing viral replication to the lowest possible level, and thereby to halt the progression of liver disease and prevent the onset of complications. Two categories of drugs are used in HBV therapy: the interferons, including standard interferon alfa or pegylated interferon alfa, and specific nucleoside or nucleotide HBV inhibitors that target the reverse-transcriptase function of HBV-DNA polymerase. The reported results of clinical trials have used varying definitions of efficacy, failure, and resistance based on different measures of virologic responses. This article discusses HBV virologic markers and tests, and their optimal use both for planning and reporting clinical trials and in clinical practice.

Through the past 2 decades, a consistent association between cigarette smoking and colorectal adenomatous polyps, recognized precursor lesions of colorectal cancer, has been shown. We performed a meta-analysis to provide a quantitative pooled risk estimate of the association, focusing on the different characteristics of the study populations, study designs, and clinical feature of the polyps.

Helicobacter pylori are spiral-shaped gram-negative bacteria with polar flagella that live near the surface of the human gastric mucosa. They have evolved intricate mechanisms to avoid the bactericidal acid in the gastric lumen and to survive near, to attach to, and to communicate with the human gastric epithelium and host immune system. This interaction sometimes results in severe gastric pathology. H pylori infection is the strongest known risk factor for the development of gastroduodenal ulcers, with infection being present in 60%-80% of gastric and 95% of duodenal ulcers.(1)H pylori is also the first bacterium to be classified as a definite carcinogen by the World Health Organization's International Agency for Research on Cancer because of its epidemiologic relationship to gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma.(2) In the last 25 years, since H pylori was first described and cultured, a complete paradigm shift has occurred in our clinical approach to these gastric diseases, and more than 20,000 scientific publications have appeared on the subject. From the medical point of view, H pylori is a formidable pathogen responsible for much morbidity and mortality worldwide. However, H pylori infection occurs in approximately half of the world population, with disease being an exception rather than the rule. Understanding how this organism interacts with its host is essential for formulating an intelligent strategy for dealing with its most important clinical consequences. This review offers an insight into H pylori host-bacterial interactions.

Hepatic fibrogenesis, the "final" common result of injury to the liver, is believed to be a critical factor leading to hepatic dysfunction and may be important in the pathogenesis of portal hypertension. Thus, accurate assessment of the degree of fibrosis is important clinically. For many years, examination of hepatic histopathology has been considered to be the "gold standard" tool used to assess fibrosis. However, liver biopsy is invasive, and in many instances not favored by patients or physicians. Thus, alternative approaches to measure liver fibrosis would be extremely attractive. To the extent that transient elastography is able to measure "liver stiffness," which is proportional to the degree of liver fibrosis, this technique holds great promise.

This document presents the official recommendations of the American Gastroenterological Association (AGA) Institute Technology Assessment on "Image-Enhanced Endoscopy." It was approved by the Clinical Practice and Economics Committee on August 3, 2007, and by the AGA Institute Governing Board September 27, 2007.

This literature review and the recommendations therein were prepared for the AGA Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on March 12, 2007, and by the AGA Institute Governing Board on May 19, 2007.

This document presents the official recommendations of the American Gastroenterological Association (AGA) Institute on "Evaluation and Management of Occult and Obscure Gastrointestinal Bleeding." It was approved by the Clinical Practice and Economics Committee on March 12, 2007, and by the AGA Institute Governing Board on May 19, 2007. This medical position statement is based upon the interpretation and assimilation of scientifically valid research, derived from a comprehensive review of published literature.

The diagnosis of inflammatory bowel disease (IBD) with its 2 main subforms, Crohn's disease and ulcerative colitis, is based on clinical, endoscopic, radiologic, and histologic criteria. This paradigm remains unchanged despite the advent of new molecular technologies for the examination of serum proteins and genetic sequences, respectively. The main innovations in diagnostic technologies include the development of more sophisticated endoscopic and noninvasive imaging techniques with the aim of improving the identification of complications, in particular malignant diseases associated with IBD. The future will see further progress in the identification of genetic susceptibility factors and of protein biomarkers and their use to describe the molecular epidemiology of IBD. It can be expected that future diagnostic algorithms will include molecular parameters to detect early disease or guide therapies by predicting the individual course of disease.

FibroTest (FT) is a biomarker of liver fibrosis initially validated in patients with chronic hepatitis C (CHC). The aim was to test two hypotheses, one, that the FT diagnostic value was similar in the three other frequent fibrotic diseases: chronic hepatitis B (CHB), alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD); and the other, that the FT diagnostic value was similar for intermediate and extreme fibrosis stages.

During the last decade, clinical practice saw a rapid increase of patients with esophageal eosinophilia who were thought to have gastroesophageal reflux disease (GERD) but who did not respond to medical and/or surgical GERD management. Subsequent studies demonstrated that these patients had a "new" disease termed eosinophilic esophagitis (EE). As recognition of EE grew, so did confusion surrounding diagnostic criteria and treatment. To address these issues, a multidisciplinary task force of 31 physicians assembled with the goal of determining diagnostic criteria and making recommendations for evaluation and treatment of children and adults with suspected EE. Consensus recommendations were based upon a systematic review of the literature and expert opinion. EE is a clinicopathological disease characterized by (1) Symptoms including but not restricted to food impaction and dysphagia in adults, and feeding intolerance and GERD symptoms in children; (2) > or = 15 eosinophils/HPF; (3) Exclusion of other disorders associated with similar clinical, histological, or endoscopic features, especially GERD. (Use of high dose proton pump inhibitor treatment or normal pH monitoring). Appropriate treatments include dietary approaches based upon eliminating exposure to food allergens, or topical corticosteroids. Since EE is a relatively new disease, the intent of this report is to provide current recommendations for care of affected patients and defining gaps in knowledge for future research studies.