Reviews & Analysis

Extraintestinal symptoms are common in patients with IBD, and can affect nearly every organ of the body. The most common manifestations include arthropathies, mucocutaneous and ophthalmological manifestations as well as manifestations of the hepatobiliary system. The authors provide a comprehensive overview of different extraintestinal manifestations and complications, including their management, in patients with IBD.

Bariatric surgery is an effective treatment for obesity, providing long-term maintenance of weight loss. Here, the authors discuss the various mechanisms by which the different types of bariatric surgery (including Roux-en-Y gastric bypass, vertical sleeve gastrectomy and adjusted gastric banding) exert their effects on body weight. Evidence from animal and human studies will be discussed.

Anti-TNF agents are effective drugs available for IBD treatment. However, antibody formation against these drugs hampers clinical effectiveness and increases risk of drug reactions. Knowledge on antibody kinetics and antibody testing is of critical importance to make well-informed decisions about starting, continuing, discontinuing and restarting of anti-TNF agents.

Hepatic encephalopathy is a severe neuropsychiatric complication of both acute and chronic liver failure. Here, the authors present new evidence that systemic and central proinflammatory mechanisms acting alone or in concert with other toxins have a role in the pathogenesis of hepatic encephalopathy. Novel diagnostic and therapeutic opportunities are also discussed.

The development of direct-acting antiviral therapies is a major advance in HCV treatment and numerous agents are in various stages of clinical development. With this rapidly changing landscape in HCV therapy, the potential of drug–drug interactions is an important aspect of management. Here, the pharmacokinetic interactions of current and investigational agents for hepatitis C are discussed.

Globally, 130–170 million people have HCV infection; however, distribution patterns are highly variable. This Review outlines the latest information on the epidemiology and natural history of HCV infection. The disease burden and mortality of HCV-related diseases, and the potential effect of HCV treatment on disease burden, are also outlined.

Pancreaticojejunostomy and pancreaticogastrostomy are both used for reconstruction after pancreaticoduodenectomy; which method is best is still debated. A nationwide multicentre randomized clinical trial that compared these two types of reconstruction has demonstrated that pancreaticogastrostomy is associated with a substantially lower rate of clinically relevant postoperative pancreatic fistula than pancreaticojejunostomy.

Serotonin (5-HT) has been recognized for decades as an important signalling molecule in the gut, but it is still revealing its secrets. Mawe and Hoffman outline the conventional and nonconventional actions of 5-HT, and describe potential therapeutic strategies targeting this molecule and its receptors.

Autoimmune gastritis is a chronic progressive inflammatory condition that results in the replacement of the parietal cell mass by atrophic and metaplastic mucosa. This Review summarizes the epidemiology, pathogenesis and pathological aspects of autoimmune atrophic gastritis. The authors also provide practical advice for the diagnosis and management of patients with this disease.

Liver transplantation has progressed from an experimental procedure to routine operation since the first human liver transplantation in 1963. This Timeline article revisits the important milestones in the development of liver transplantation, discussing how the procedure has evolved over time and what challenges are still to overcome.

The association ofHelicobacter pylori infection with peptic ulcers was published in 1984. Here, Kwong Ming Fock, David Y. Graham and Peter Malfertheiner provide their insights into the advances in H. pyloriresearch over the past 30 years and where research should be targeted in the future.

Haemorrhoid disease is the most frequent proctologic complaint. The management of haemorrhoids has evolved rapidly during the past few decades. Here, the authors describe the current treatment options for the effective management of patients with grade I–IV haemorrhoids, presenting both conservative and surgical approaches.

New data from a large cohort study describe an increased risk of intrahepatic cholestasis of pregnancy (ICP) in women with prior hepatobiliary disease and confirm the association between ICP and subsequent disease. These findings should prompt a change in clinical practice for guidelines to recommend hepatitis C screening for women with ICP.

Excessive consumption of alcohol can have serious physical, psychological and social implications. Alcohol dependence is a complex genetic disease, with variants in many different genes affecting a person's risk of becoming dependent on alcohol. Here, the authors discuss the genetic factors underlying this disorder.

Colorectal cancer is a heterogeneous disease, with at least three well-known major, molecularly defined groups: the chromosomal instable, the microsatellite instable and the CpG island methylator phenotype. Although these groups differ in pathology, outcome and response to therapy, this classification is not used in clinical management. Two recent studies might change this perception.

This Review summarizes current knowledge on the role of different microRNAs (miRNAs) in liver diseases. The functions of the most relevant miRNAs that have specific roles in liver damage, hepatocyte functions, viral hepatitis, alcoholic and nonalcoholic liver disease, liver fibrosis and hepatocellular carcinoma are highlighted. The emerging utility of miRNAs as potential biomarkers in liver diseases is also discussed.

Emerging evidence indicates that the intestinal microbiota influence brain chemistry, development and behaviour in animals. Tillisch and colleagues now show that ingestion of selected probiotics changes brain connectivity and responses to emotional challenge in healthy humans, paving the way for therapeutic exploitation of the microbiome–brain axis for functional gastrointestinal and primary behavioural disorders.

Gastrointestinal motility disorders are common in clinical practice. In this Review, the authors present an overview of the currently available gastrointestinal motility and function tests that are used to establish a diagnosis of functional disorders.

Postoperative recurrence (POR) frequently occurs in patients with Crohn's disease, but current medications have proven of little benefit for this indication. In this Review, Dario Sorrentino outlines the definition, the main modalities of diagnosis and the risk factors for POR. The various medications and approaches used to prevent POR are also discussed and an algorithm for prevention of POR is proposed.

Liver transplantation is a risky business and donated organs are second-hand. Grafts carry risk and the surgeon must match the graft with the recipient. Macrosteatosis >30% is associated with poor outcomes, but assessment is not straightforward; for once, a study has shown that clinical assessment might be just as reliable as more sophisticated and objective measures.