Reviews & Analysis

Improved knowledge of the complex pharmacology, metabolism, mechanism of action, and toxicity profile of thiopurines has guided the development of strategies to improve pharmacotherapy in patients with IBD. This Review discusses the clinical implications of these developments, such as reducing the risk of adverse events (e.g. myelodepression and hepatotoxicity) by genetic screening, metabolite level characterization, and dose reductions.

The local staging and management of rectal cancer has evolved in the past decade. Imaging modalities used for staging rectal cancer include computed tomography, endoscopic ultrasound, magnetic resonance imaging, and positron emission tomography. In this Review, the author discusses the strengths and limitation of these modalities, along with the management of rectal cancer.

Any worthwhile guideline must be evidence-based, or should it? Evidence for the construction of guidelines often comes from clinical trials that are performed in the West according to the priorities and goals of that population and those of the pharmaceutical industry whose resources are relied upon to perform such trials. This Viewpoint article discusses the development of guidelines using an evidence-based approach and whether this approach is applicable worldwide.

Clinical Guidelines are primarily developed in the affluent West. This Viewpoint article discusses whether these guidelines are really useful and relevant to resource-poor, developing countries, and whether attempts to adhere to such guidelines obscure more fundamental issues such as the provision of basic health care. The authors argue that if guidelines are adapted to local resources and needs, and employ a 'cascade' approach they can work.

Evidence-based guidelines from wealthy countries define optimum goals for resource-constrained countries. This Viewpoint article discusses how health-care policy in developing countries can only be influenced through local involvement in the construction and implementation of guidelines. The authors also discuss the potential yet controversial role of the biomedical industry in facilitating the development and dissemination of global guidelines.

Clinical understanding of IBS has been advanced considerably by studying a small subgroup of patients who develop IBS acutely after an episode of infectious gastroenteritis. This Viewpoint article discusses post-infective IBS and how psychosocial and gut-specific factors (including activation of the gut mucosal immune system) interact to produce IBS symptoms.

This Case Study describes a 24-year-old white male with Crohn's disease that was in remission who presented with cholestasis and hyperbilirubinemia. The patient had normal alanine aminotrasferase and γ-globulin levels, and the results of serological tests for an infectious cause of hepatopathia were negative. The patient was diagnosed with autoimmune hepatitis–primary sclerosing cholangitis overlap syndrome on the background of primary sclerosing cholangitis.

Twenty years ago, hepatopulmonary syndrome (HPS) was an absolute contraindication to orthotopic liver transplantation (OLT). HPS patients are now included on the waiting list for OLT because of reports that indicated survival after OLT in patients with hypoxemia had improved, the discovery that HPS can resolve after OLT, and the lack of other effective treatments. This Review provides an overview of information pertinent to the diagnosis of HPS and its management in OLT candidates.

This Review discusses the most common causes of chronic cough, the clinical features of GER-related cough and the usefulness of an empiric therapy trial to identify and treat these patients. The authors also consider how to proceed when patients do not improve with an empiric therapy trial. Clinical outcomes, long-term GER therapy and potential pitfalls of the treatment of GER-related cough are also covered.

The authors of this Review provide an overview of the mechanisms by which HCV is currently understood and postulated to govern liver injury. These mechanisms include the regulation of apoptosis, steatosis, activation of hepatic stellate cells, and the cytotoxic lymphocyte response.

Most patients with hepatocellular carcinoma have underlying liver disease and the optimal treatment is, therefore, liver transplantation. When liver transplantation is not possible clinicians must decide whether to resect or ablate the cancer. The author of this Viewpoint article discusses the advantages and disadvantages of these two approaches and their use in clinical practice.

Acute appendicitis remains one of the abdominal diseases most commonly requiring emergency treatment. Successful nonsurgical management of appendicitis has raised the possibility of treating this condition with antibiotics alone. The author of this Viewpoint article examines the available evidence for this therapeutic approach and discusses its role in clinical practice.

Convincing new evidence suggests that mild hypothermia prevents intracranial hypertension and its complications in patients with acute liver failure. This Viewpoint examines available data for the use of mild hypothermia as a novel therapy in this setting, and calls for controlled clinical trials and systematic studies of its potential adverse effects.

Colonoscopy is increasingly being used for colorectal cancer screening, which has resulted in a growing cohort of patients who have polyps and require postpolypectomy surveillance. In this Review, the authors present an overview of the new postpolypectomy surveillance guidelines, explain the rationale behind them, discuss barriers to their implementation, and examine strategies to overcome these barriers.

Rectal prolapse causes significant discomfort because of the sensation of the prolapse itself, the mucus that it secretes, and because it tends to stretch the anal sphincters and cause incontinence. Treatment is primarily surgical; however, there are different opinions about which type of surgical repair is best. The authors of this Review discuss the pathogenesis, clinical presentation, evaluation and surgical management of rectal prolapse.

Although the incidence of stress-induced gastrointestinal bleeding has decreased, such bleeding is associated with increased morbidity and mortality in critically ill patients. In this Review, the authors address some of the issues surrounding treatment for the prevention of stress-induced gastrointestinal bleeding, such as whether all patients need prophylaxis, and how long prophylaxis should be continued for.

Over the past 15 years, intestinal transplantation for the treatment of intestinal failure has changed from a desperate last-ditch effort into a standard therapy for which a good outcome is expected. In this Review, the author considers several issues surrounding intestinal transplantation, including patient selection, allograft type, outcomes, complications, post-transplant monitoring and cost.

The authors of this Review discuss the diagnosis, clinical features and genetics of the hamartomatous polyposis syndromes, as well as the risk of malignancy associated with each syndrome and appropriate surveillance recommendations. Other disorders associated with the presence of hamartomatous polyps are briefly discussed, along with the potential for targeted therapy of hamartomatous polyposis syndromes.