Reviews & Analysis

The role of psychological distress in provoking and exacerbating IBD is controversial. This Viewpoint discusses the role of psychological factors in the pathogenesis of IBD and focuses on the need for including psychological care in the clinical management of patients with IBD.

Cholangiocarcinoma is, in most cases, rapidly fatal, having an inadequate response to the treatment strategies currently available. The authors of this Review describe the mechanism of action, efficacy and complications of photodynamic therapy—a relatively new local, minimally invasive treatment for cholangiocarcinoma that uses the photo-physical properties of photosensitizers to destroy tumors.

Pathogenic intestinal protozoa are responsible for clinically important infections in both the developed and developing world. Treatments have been available for several decades for giardiasis, isosporiasis and amoebiasis, but until recently there were no effective remedies for the intestinal coccidia—cyptosporidium, microsporidium and cyclospora. In this Review, the author discusses the various pathogenic intestinal protozoa and the treatment options available.

The treatment of chronic hepatitis B has improved substantially in recent years. FDA-approved therapies now include interferon α, pegylated interferon α2a, lamivudine, adefovir dipivoxil, and entecavir. Other antiviral agents and combination regimens are in various stages of development. This Review summarizes the results obtained for approved therapies and highlights emerging antiviral agents for the treatment of chronic hepatitis B.

The treatment of idiopathic acute pancreatitis is challenging owing to its varied etiology. This Viewpoint discusses the use of empiric cholecystectomy as a definitive treatment option for idiopathic acute pancreatitis caused by occult gallstone disease, and compares cholecystectomy with other treatment options including biliary sphincterotomy and medical therapy with ursodeoxycholic acid.

Intestinal detoxification and defense systems are important for maintaining normal gut physiology. This Viewpoint presents the concept that inflammatory bowel disease might be caused by a defective mucosal detoxification system. Polymorphisms in detoxification genes and related endobiotic plasma biomarkers might both support diagnosis, stratification and therapy in patients with inflammatory bowel disease.

In the past few years, data obtained from work in animal models, human genetics, basic science and clinical trials, has provided new insights into the mechanisms underlying Crohn's disease and ulcerative colitis. In this review, the author discusses the evidence underlying the disparate theories on the pathogenesis of these diseases and attempts to reconcile them into a coherent hypothesis based on the experimental data.

This Review considers the pathophysiologic basis for transjugular intrahepatic portosystemic shunt (TIPS) placement in cirrhotic patients with refractory ascites. The effect of TIPS placement on hemodynamics and sodium retention is discussed, along with how TIPS placement compares with large-volume paracentesis–the standard therapy for refractory ascites. Disadvantages of the procedure, predicting mortality after TIPS placement, candidate selection and monitoring after TIPS placement are also covered.

Colorectal cancer claims more than 50,000 lives annually in the US. Screening for colorectal cancer, with the removal of any identified polyps, significantly impacts the death rate from this largely preventable cancer. This Viewpoint discusses the relative merits and pitfalls of colonoscopy and CT colonography as screening modalities in the setting of colorectal cancer.

A constellation of cardiac abnormalities, including blunted contractile responses to stress and repolarization abnormalities, can be found in patients with cirrhosis. So-called cirrhotic cardiomyopathy is now recognized as a significant contributor to morbidity and mortality. In this Review, the authors discuss the clinical features of cirrhotic cardiomyopathy, pathogenic mechanisms underlying the condition, and general diagnostic criteria and treatment measures for cirrhotic cardiomyopathy.

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.