Reviews & Analysis

Hepatorenal syndrome, which is characterized by functional renal failure secondary to renal vasoconstriction in the absence of underlying kidney pathology, is a feared complication of cirrhosis. This Review focuses on the pathogenesis, clinical features, and diagnosis of hepatorenal syndrome. The authors also consider current management options, which include liver transplantation, pharmacologic therapies, transjugular intrahepatic portosystemic shunt placement and albumin dialysis.

Ursodeoxycholic acid has been administered as a remedy for liver diseases since the time of the Tang dynasty. Today, it is used to treat cholestatic liver diseases, such as primary biliary cirrhosis, primary sclerosing cholangitis and intrahepatic cholestasis of pregnancy. This Review considers what is currently known about the potential mechanisms and sites of action underlying the anticholestatic effect of ursodeoxycholic acid.

This Viewpoint looks at the possible reasons why the publication of medical errors in the scientific literature is so infrequent, not only when compared with the number and variety of medical errors that occur, but also in view of the didactic importance of debating mistakes and possible ways to avoid them.

Pancreatic cancer has an extremely poor natural course, and early diagnosis is difficult owing to its location and the lack of early markers for the disease. This Viewpoint discusses whether it is possible to survive pancreatic carcinoma in light of these features, in addition to examining current and potential future therapies.

Over the past decade, there have been remarkable advances in our understanding of stem cell biology. Although the intestinal stem cell remains difficult to isolate, it is known to be important for the development of intestinal neoplasms. In this Review, the authors discuss the basic mechanisms behind stem cell regulation in the gut and their role in the natural history of tumor progression in the setting of colorectal cancer.

The authors of this Review consider how a reduced prevalence of organisms that have been part of human microecology for millennia (including saprophytic mycobacteria, bifidobacteria, lactobacilli, and helminths) and cause little, if any, harm to the host, might explain the increased prevalence of immune-mediated disorders in westernized countries.

The management and treatment of gastrointestinal ailments in pregnant women require special attention and expertise because of the safety of the mother, fetus and neonate remains the primary focus. The authors of this Review discuss pharmacologic therapies for gastrointestinal conditions encountered during pregnancy, including nausea and vomiting in pregnancy, hyperemesis gravidarum, gastroesophageal reflux disease, peptic ulcer disease, irritable bowel syndrome and inflammatory bowel disease.

A wide range of expert opinions exist on the ideal case definition for hemochromatosis, and much of the debate centers on its phenotypic or genotypic diagnosis. The author of this Viewpoint discusses the controversy involved in establishing a diagnosis for the disease and provides recommendations for an appropriate case definition.

The number of patients using alternative and complementary therapies is increasing worldwide, and a large percentage have inflammatory bowel disease. This Viewpoint considers evidence for the safety and efficacy of these therapies for the treatment of inflammatory bowel disease, and the reasons why patients choose to seek alternatives to conventional medicine.

Advances in the understanding of the pathogenesis of inflammatory bowel disease have allowed rational therapeutic targets to be developed, including antagonists of tumor-necrosis factor-α. The authors of this Review provide insights into the similarities and differences of the mechanism of action, clinical efficacy and limitations of the tumor-necrosis factor-α antagonists infliximab, adalimumab, certolizumab, CDP571, etanercept, and onercept.

Malnutrition is an increasingly recognized complication of chronic liver disease. In patients with cirrhosis, malnutrition increases morbidity and mortality, and patients who are severely malnourished before transplantation have a higher rate of complications and higher post-operative mortality. The authors of this Review consider the etiologies of malnutrition, methods used to assess nutritional status, and appropriate treatment strategies.

Esophageal impedance monitoring is a new technique that can be used alone and in combination with pH-metry and manometry to evaluate bolus transport and all types of gastroesophageal reflux. The authors of this Review describe the technique and summarize the published validation studies that compare impedance monitoring with other methods. Normal values and the reproducibility of impedance patterns and their association with symptoms are also discussed.

The pathogenesis of hepatic encephalopathy and cerebral edema in patients with acute liver failure has yet to be fully elucidated. This Viewpoint considers whether infection and inflammation have a role to play, and discusses emerging data on the molecular pathways that could link ammonia to infection and inflammation in this setting.

Video capsule endoscopy (VCE) is the most recent major practical and conceptual advance in the field of endoscopy, and its widespread deployment in gastrointestinal practice suggests that it is has achieved mainstream use. In this Review, the author considers the indications for VCE, practical issues (such as patient selection and bowel preparation), and the limitations and complications of VCE, and discusses what VCE's future might hold.

The correlation between the endoscopic impression of gastritis and histologic gastritis is poor and there are few well-known histologic gastritides that yield specific diagnoses. Gastroenterologists might therefore be frustrated by the surgical pathology report accompanying a set of gastric biopsies. The authors of this Review explain common pathologic diagnoses of gastric inflammation and address communication deficiencies between pathologists and gastroenterologists.

Metoclopramide is one of the most widely used drugs for gastroenterological motility disorders, but it has many potentially troublesome neurological adverse effects, particularly movement disorders. The authors of this Review discuss the indications for metoclopramide, its side effects and common pitfalls of prescribing metoclopramide, and describe strategies to minimize the medicolegal risks to the prescribing physician.