The aim of our study was to examine the prevalence of gastric myoelectrical disturbances in relation to gastrointestinal motility abnormalities in patients with functional dyspepsia, using simultaneous electrogastrography and antroduodenojejunal manometry. We carried out electrogastrography in 20 patients with functional dyspepsia and in 20 healthy volunteers. In 10 of these patients and in 10 of the volunteers antroduodenojejunal manometry was performed simultaneously. Apart from a higher postprandial power content of the 3 cycles per minute (cpm) component in the patients (1263 +/- 317 and 393 +/- 101 microV2, respectively; P = 0.016), no differences in the electrogastrographic variables were found between the groups. In the manometric part of the study, postprandial antral hypoactivity was not a prominent finding. Instead, small intestinal hyperactivity was found in the dyspeptic patients, with both a higher frequency and amplitude of the contractions (P < 0.05). This hyperactivity often consisted of bursts, which were significantly more frequent in patients than in control subjects (total duration of burst activity 25.6 +/- 6.4 and 6.0 +/- 1.7 min, respectively; P = 0.013). A positive correlation was found between the frequency of the gastric electrical control activity and the antral contraction frequency (P = 0.006), between the power content of the electrographic signal and the antral contraction amplitude (P = 0.025), and between the postprandial/fasting electrographic power ratio and the antral motility index (P = 0.007). In conclusion, gastric myoelectrical activity is minimally disturbed in patients with functional dyspepsia. Motor abnormalities, especially small intestinal hyperactivity, are more likely to play a prominent role in the genesis of dyspeptic symptoms.