BACKGROUND/AIMS: A decreased perception threshold of gastric distension has been observed recently in selected patients with functional dyspepsia(FD) in the absence of changes in gastric compliance. The sensations induced by changes in intragastric pressure and volumes have been shown to be independent of gastric emptying times. In Korea, there has been no report about the response to gastric distension using electronic barostat in patients with FD. Thus, we aimed to evaluate whether decreased perception threshold to the gastric distension could be one of the pathogenic factors in FD. METHODS: Thirty patients with dysmotility-like FD(9 men and 21 women; age range, 27-57 years) and 20 healthy individuals without gastrointestinal symptorns(10 men and 10 women; age range, 20-54 years) were included in this study after receiving written informed consent. We measured intragastric minimal distending pressure(MDP), gastric compliance, aMominal discomfort level, and gastric emptying rate of solid meal. We used a dual drive barostat (G and J Electronics, Canada) and biad gamma camera(Trionix). MDP was defined as the first pressure level to inflate an intra gastric bag volume > 30mL. And then, symptoms and volume of the intragastric bag, which was inflated by increasing intragastric bag pressur, was measured in 1 mmHg steps every 3 minutes, We compared gastric compliance at a low pressure zone(0-2 mmHg above MDP) and at a high preassre zone(6-8mmHg above MDP), We calculated the mean values( SD) of the parameters, and statistical comparisons were performed using tbe repeated measures ANOVA. RESULTS: The MDP was significantly decreased in FD(3.9>1.8 mmHg) compared to the controls(5.7+ 1.7 mmHg; p<0.001). The gastric compliance(Cw) at a high pressure zone was significantly higher in FD(46.5+30.6 mL/rnmHg) compared to the control(31.3 + 15.3 mL/mmHg; p<0.05). Whereas there was no difference in compliance(C) at the low pressure zone(41.2+25.6 mL/mmHg in FD vs. 43.9+23.1 mL/mmHg in the control). Patients with FD had gastric hypersensitivity to distension(discomfort threshold at 8.3+3.8 mmHg and 392+109 mL in FD vs. 14.S+3.8 mmHg and 558+135 rnL in controls; p<0.001). There were no differences in MDP, compliance, and discomfort level according to gastric emptying times. CONCLUSIONS: We conclude that decreased perception threshold to gastric distension could be a pathogenic factor, and also an increased gastric compliance at high pressure zone may play a pathogenic role in FD.