Objective : To investigate the therapeutic effect of manual acupuncture at Siguan (four gates, bilateral LI4 and LR3) on suppression of gastrointestinal motility. Methods : A single blind, randomized, sham-acupuncture controlled, crossover study was conducted. Twenty healthy male subjects were admitted at hospital, and gastrointestinal motility suppression was induced by loperamide administration. Just after intake of 20 radio-markers, four gates or sham acupoint treatments were administered every 12 hours, 4 times over 48 hours. Gastrointestinal motility was evaluated by radiographic distribution of the radiomarkers at stomach or ileum, ascending, transverse, descending colon, sigmoid/rectum, and outside body at serial time points (0, 6, 12, 24, and 48 h). Results : Four gates acupuncture activated gastrointestinal movement as evidenced by significantly changed distributionof radio-makers at 6, 12, and 48 hours (P < 0.0001, P = 0.001, and P = 0.03, respectively) in Cochran-Mantel-Haenszel statistics. No serious adverse events occurred in either group. Conclusions : This study showed a scientific clinical relevance of four gates acupuncture to gastrointestinal disorders.