Daikenchuto (TU-100) is a traditional Japanese Kampo medicine composed of four crude drugs: dried Japanese pepper, processed ginger, ginseng radix and maltose powder. TU-100 is traditionally used in the treatment of chronic gastrointestinal disorders, and often prescribed to relieve abdominal pain, abdominal distention, Crohn’s disease, irritable bowel syndrome, adhesive ileus, and paralytic ileus. TU-100 improves gastrointestinal dysmotility and reduces serum CRP levels in patients with grade B liver damage after hepatectomy. TU-100 is an effective treatment option after hepatic resection in patients with liver cancer. Although the effects of TU-100 on gastrointestinal motility have been unexplored, recent studies have revealed its various other effects, including the following: firstly, an anti-inflammatory response through the selective inhibition of cyclooxygenase-2 (COX-2) and/or down-regulation of several inflammatory mediators such as tumor necrosis factor-a, interleukin-1b and endothelin-1; secondly, the prevention of bacterial translocation; and thirdly, the increase of gastrointestinal blood flow through the induction of calcitonin gene-related peptide (CGRP), substance P and vasoactive intestinal polypeptide (VIP). TU-100, which is manufactured by Tsumura & Co. (Tokyo, Japan), has been approved by the US Food and Drug Administration as an investigational drug, and several placebo-controlled double-blind trials have been launched in the US to investigate its use for constipation and Crohn’s disease. TU-100 was approved for manufacture as a prescription drug in 1986 by the Japanese Ministry of Health and Welfare and has been sold commercially as a prescription Kampo (a generic term for the system of traditional medicine that was developed in Japan after being introduced from China in the fourth century) drug in Japan for many years.