Japanese herbal medicine in functional gastrointestinal disorders.

Management of functional gastrointestinal disorders is hindered by both poor efficacy and adverse effects of traditional pharmacological therapy. Herbal medicine may be an attractive alternative based on the perception of its 'natural' approach and low risk of side effects; however, the lack of standardization of drug components has limited the ability to perform rigorous clinical studies in Western countries. Japanese herbal medicine (JHM) is a standardized form of herbal medicine with regards to the quality and quantities of ingredients. While extensively studied and widely used in Asia, there is a paucity of data upon which physicians in other parts of the world may draw conclusions regarding the effectiveness of herbal medicine for gastrointestinal disorders. The aim of this study was to summarize the most recent developments in JHM for treatment of functional gastrointestinal disorders. Animal and human studies were systematically reviewed to identify published data of JHM used for treatment of gastrointestinal disorders. The herbal components of JHM were examined. Results describing the physiological and clinical effects of JHM were abstracted, with an emphasis on functional gastrointestinal disorders. JHM are associated with a variety of beneficial physiological on the gastrointestinal system. Patient-based clinical outcomes are improved in several conditions. Rikkunnshi-to reduces symptoms and reverses physiological abnormalities associated with functional dyspepsia, while dai-kenchu-to improves symptoms of postoperative ileus and constipation in children. This updated summary of JHM in the field of gastrointestinal disorders illustrates the potential for herbal medication to serve a valuable role in the management of patients with functional gastrointestinal disorders.