Reviews & Analysis

Nutritional support is an established and routine part of patient management. Conventionally, enteral nutrition is preferred to parenteral nutrition, because studies have indicated that enteral nutrition causes fewer complications. In this Review, the author critically analyzes the available data that compare these administration routes, and suggests that the effect of hyperglycemia, energy intake and obesity are perhaps more important than the route of nutrition in determining outcome.

The authors of this Review discuss the increased risk of morbidity and mortality associated with surgery in patients with underlying liver disease, and describe the essential role that preoperative assessment has in these patients. The nature and severity of the underlying liver disease and the type of surgery being undertaken are all considered and guidelines for preoperative assessment provided.

Although the introduction of parenteral nutrition revolutionized the care of premature babies, long-term parenteral nutrition incurs the risk of life-threatening hepatic complications. The authors of this Review discuss the fundamentals of parenteral nutrition associated cholestasis, animal models of the disease, transporters crucial for bile acid homeostasis, and the molecular pathogenesis of this life-threatening condition.

This Viewpoint highlights the apparent shift in ulcer epidemiology, with regard to the observed increase in the prevalence of non-Helicobacter pylori, non-NSAID, idiopathic ulcers. The authors recommend that the underlying cause of idiopathic ulcers be investigated further, with rigorous use of diagnostic techniques, and that efforts be made to improve the management and prevention of this condition.

The worldwide incidence of morbid obesity is rapidly increasing. When considering how to treat morbid obesity there are two surgical treatments—laparoscopic adjustable gastric banding and gastric bypass—that go head to head. This Viewpoint examines the safety and efficacy of laparoscopic adjustable gastric banding and gastric bypass for achieving weight loss, and their ability to resolve comorbidities such as type 2 diabetes mellitus.

In the past decade, there have been significant advances in the three techniques classically used for liver imaging—ultrasonography, CT and MRI. In this Review, the authors highlight the advances in these techniques that apply to the assessment of focal and diffuse liver disease, including the development of hardware, software, processing algorithms, and procedural innovations.

The authors of this Review discuss current indications for treatment in patients with autoimmune hepatitis, conventional management regimens, therapeutic end points and treatment outcomes. Factors that influence the treatment response, empiric salvage therapies, and promising pharmacological and molecular interventions are also considered.

Diagnosis of obscure gastrointestinal bleeding is challenging for gastroenterologists. Capsule endoscopy has revolutionized examination of the small bowel in this setting, but has several limitations. Double balloon enteroscopy is a new technique that also allows for extensive evaluation of the small bowel. This Viewpoint examines the usefulness of these techniques in clinical practice.

Leptin is involved in many biological processes that implicate it in the development of colorectal cancer. This Viewpoint discusses the biological plausibility of a relationship between leptin and colorectal cancer, and the evidence available to support such a relationship.

MRI, and magnetic resonance cholangiopancreatography in particular, is completely noninvasive and allows imaging of the pancreas, as well as the biliary and pancreatic ducts. Technical advances, including the administration of secretin, have improved the quality of the pancreas and pancreatic duct images obtained. The authors of this Review assess the current status of MRI for the evaluation of benign pancreatic disease.

In this Review, the authors examine the most recent clinical evidence for the use of sulfasalazine and mesalazine for the treatment of ulcerative colitis and Crohn's disease. Evidence for the role of mesalazine as a chemoprophylactic agent that protects against the development of colorectal cancer is also discussed.

Bariatric surgery is an effective long-term treatment for morbid obesity. This Review discusses the indications for bariatric surgery and the early and late complications associated with the two most commonly performed bariatric procedures–laparoscopic gastric bypass and laparoscopic adjustable silicone gastric banding. Laparoscopic biliopancreatic diversion and laparoscopic sleeve gastrectomy are also briefly discussed.

The treatment of chronic hepatitis C is rapidly evolving. Current treatment modalities are being refined, and entirely new, specifically targeted, antiviral therapies (known as STAT-C) that inhibit the various steps of viral replication are being developed. This Viewpoint discusses the status of agents in development and their implications for the future treatment of hepatitis C.

It has been suggested that genetic factors are likely to have a major role in the manifestation of functional gastrointestinal disorders. In this Review, the authors consider the evidence available for such a role. They discuss the results of family and twin studies and studies of individual genes thought to be involved in the manifestation of functional gastrointestinal disorders.

Severe ulcerative colitis is considered a medical emergency, the management of which requires close collaboration between gastroenterologists and surgeons. The authors of this Review discuss the identification of prognostic factors and intensive medical treatment for both uncomplicated and complicated ulcerative colitis, as well as the timing of surgery.

The efficacy of biologic therapies is proven and their use is growing worldwide; however, there is concern about their long-term safety, including the risk of developing cancer. In this Review, data available on the association of anti-tumor necrosis factor therapies and the anti-α4 integrin monoclonal antibody natalizumab with cancer in patients with IBD are discussed.