To evaluate the role of gastric hypersensitivity and the relationship between gastric hypersensitivity and delayed gastric emptying in Korean functional dyspepsia (FD) patients, the authors performed gastric barostat and gastric emptying scintigraphy in 64 FD patients and compared these results with those of control subjects. Basal tones and gastric compliance were similar in control subjects and patients. However, threshold of abdominal discomfort was lower in FD patients than in control subjects (8.9 +/- 3.6 mmHg and 14.5 +/- 3.7 mmHg respectively; p < 0.05). Twenty-four of 64 patients (37.5%) experienced abdominal discomfort at a pressure less than 7 mmHg above minimal distending pressure (corresponding to the 95th percentile of normal values). Half time of solid-phase gastric emptying in patients and control subjects was not significantly different. Twenty-three of 64 patients (35.9%) had delayed gastric emptying compared with control subjects (normal ranges were mean +/- two standard deviations in control subjects). Thresholds of abdominal discomfort were not significantly different in patients with and without delayed gastric emptying (9.3 +/- 4.0 mL/mmHg vs. 8.6 +/- 3.3 mL/mmHg). There were also no significant differences in the proportion of patients with delayed gastric emptying between patients with and without gastric hypersensitivity. In conclusion, gastric hypersensitivity plays an important role in FD, and the presence of gastric hypersensitivity was not related to the presence of delayed gastric emptying.