Reviews & Analysis

IBS affects up to 15% of the population and continues to provide the medical profession with diagnostic and therapeutic challenges. The pathophysiology is complex and until it is better understood management strategies will necessarily remain rather empirical.

Portal vein thrombosis occurs frequently in patients with cirrhosis, but it is unclear whether it is a cause or consequence of decompensation in cirrhosis. The heterogeneity of data on the influence of portal vein thrombosis on the natural history of cirrhosis has been added to in a new study.

Since the discovery of HBV in the 1960s, its life cycle and the natural history of infection have been delineated by many studies. In 2014, new findings concerning the host–virus interaction and new studies of HBV reactivation from occult HBV infection are of considerable interest.

Several key studies published in 2014 have shed light on the pathogenesis of IBD by investigating the molecular mechanisms controlling mucosal homeostasis and intestinal barrier function. These studies revealed that alterations of intestinal homeostasis drive chronic intestinal inflammation. Here, we describe these findings and discuss future directions for translational research in IBD.

Oesophageal cancer is characterized by poor prognosis, and curatively intended treatment is extensive and demanding. In 2014, well-designed clinical studies have advanced our knowledge of how to improve the treatment of oesophageal cancer at various tumour stages.

Evidence is mounting that molecular mechanisms underlie gut dysfunction and symptom generation in IBS. Although it is still an uphill struggle, this mounting evidence is a good starting point for the discovery of one or more IBS biomarkers.

The pathophysiology of IBS is complex with a number of different factors involved. Here, the authors highlight crosstalk between the gut microbiota, enteroendocrine system, immune system (including neuroimmune interactions) and intestinal permeability in the development of IBS. Insights into how these entities might interact are discussed.

Patients with IBD might be at increased risk of cardiovascular disease and stroke. This Review discusses the epidemiology, pathophysiology, risk factors (in particular, the role of IBD activity and IBD-related medications) and management of cardiovascular disease in patients with IBD. The potential effects of cardiovascular medications on IBD are also discussed.

The best time point to determine cure of chronic hepatitis C was explored in a retrospective analysis of five published trials of sofosbuvir–ribavirin with or without PEG-IFN. The authors conclude that SVR12 can be used effectively to determine 'cure' rates in trials and in clinical practice.

Oesophageal dysphagia is considered to be an 'alarm symptom' related to diseases such as oesophageal carcinoma and more commonly, functional disorders. Frank Zerbib and Taher Omari discuss the different aetiologies and clinical presentation of oesophageal dysphagia. In addition, they outline the use of endoscopy, biopsy and high resolution manometry for diagnosis.

The association that the mycobiome has with gastrointestinal health and disease is gradually being revealed using state-of-the-art sequencing technologies. This Review presents the latest research on the interaction between fungi, bacteria and the host in relation to gastrointestinal disease, in particular IBD and graft-versus-host disease. The authors point out that further research is needed in this developing area of science and highlight areas of future endeavour.

The origin of Barrett oesophagus has been debated for many years, but no consensus has been reached. In this Perspectives article, Stuart McDonald and colleagues look at the Barrett lesion itself: at its phenotype, its complexity, its clonal architecture and its stem cell organization. They conclude that current evidence most strongly supports an origin from stem cells in the cardia.

IBD has emerged as a global disease. Ng and colleagues have identified that some environmental risk factors are shared across the world, whereas others are distinctly unique to individuals living in Asia. This work adds a new clue to the mystery of the environmental determinates of IBD.

Little progress has been made in the pharmacological management of patients with hepatic encephalopathy, partly because it is difficult to perform clinical trials in this group of patients. A new clinical trial now suggests that polyethylene glycol is more effective than the current standard first-line therapy in these patients.

Optimization of biologic therapies in IBD represents an important therapeutic strategy to improve clinical outcomes. Vaughn and colleagues have analysed the long-term benefits of proactive therapeutic concentration monitoring of infliximab in patients with IBD.

Failure to control acute variceal bleeding is a strong predictor of mortality in patients with cirrhosis. Various criteria have been proposed to define failure to control bleeding for use as end points in randomized clinical trials. However, the clinical applicability and validation of these proposed criteria remain unresolved issues.

IBD is known to be associated with an abnormal response to an unbalanced gut microbiota in genetically predisposed individuals. The therapeutic goal now is to control progression of the disease. Given the heterogeneity of IBD, the two universes of basic and clinical science must work in parallel to realize the hope of personalized therapy.

Five of our Advisory Board Members—international experts across different subspecialties—reflect on the progress and frustrations of the past 10 years in gastroenterology and hepatology. They also comment on where effort and money should be invested now, as well as their predictions for progress in the next 10 years.

Polycystic liver diseases are inherited in a dominant or recessive form and result in progressive bile duct dilatation and/or cyst development. Current therapeutic strategies are limited and the only curative option is liver transplantation. This Review discusses the molecular mechanisms that cause polycystic liver diseases and preclinical and clinical studies into new therapeutic targets. The authors also highlight future avenues of research.

Coeliac disease is a common gastrointestinal disease that can present at any age. Previous diagnosis relied on duodenal biopsy however contemporary techniques of antibody detection and determination of genetic susceptibility using HLA genotyping have improved diagnostic accuracy and reduced the our reliance on biopsy samples. This Review discusses the diagnostic process in children, adolescents and adults in light of the progress that has been made in developing accurate coeliac disease diagnostic tools.