Review article: current and emerging therapies for functional dyspepsia.

Functional dyspepsia represents a heterogeneous group of gastrointestinal disorders marked by the presence of upper abdominal pain or discomfort. Although its precise definition has evolved over the last several decades, this disorder remains shrouded in controversy. The symptoms of functional dyspepsia may overlap with those of other functional bowel disorders including irritable bowel syndrome and non-erosive reflux disease. There may be coexistent psychological distress or disease complicating its presentation and response to therapy. Given the prevalence and chronicity of functional dyspepsia, it remains a great burden to society. Suspected physiological mechanisms underlying functional dyspepsia include altered motility, altered visceral sensation, inflammation, nervous system dysregulation and psychological distress. Yet the exact pathophysiological mechanisms that cause symptoms in an individual patient remain difficult to delineate. Numerous treatment modalities have been employed including dietary modifications, pharmacological agents directed at various targets within the gastrointestinal tract and central nervous system, psychological therapies and more recently, complementary and alternative treatments. Unfortunately, to date, all of these therapies have yielded only marginal results. A variety of emerging therapies are being developed for functional dyspepsia. Most of these therapies are intended to normalize pain perception and gastrointestinal motor and reflex function in this group of patients.