The effect of traditional Japanese medicine (Kampo) on gastrointestinal function.

Traditional Japanese medicine (Kampo) is used to treat various disorders of the gastrointestinal tract in Japan, where it is fully integrated into the modern healthcare system. Recently, scientific research on herbal medicine in Japan has been reported in English journals. The objective of the current review is to introduce two traditional Japanese medicines and to provide evidenced-based information regarding their use. Daikenchuto, which consists of three different herbs, is the most frequently prescribed traditional Japanese medicine in Japan. Daikenchuto stimulates gastrointestinal motility though a neural reflex involving presynaptic cholinergic and 5-HT3 receptors. Daikenchuto improves postoperative bowel motility and postoperative ileus. Furthermore, it is reported to cause an increase in gastrointestinal hormones (motilin, vasoactive intestinal peptide, and calcitonin gene-related peptide) and intestinal blood flow. Rikkunshito, a traditional Japanese medicine consisting of eight herbs, is thought to stimulate gastrointestinal motility and ghrelin secretion. Rikkunshito is effective for improving the symptoms of functional dyspepsia, gastroesophageal reflux disease, and cisplatin-induced anorexia and vomiting. Traditional Japanese medicine has the potential to be used successfully in the treatment of gastrointestinal disorders. Details regarding the physiological and clinical effects of traditional Japanese medicine must be further examined in order to become more widely accepted in other countries.