RESPONSES TO GASTRIC DISTENSION IN FUNCTIONAL DYSPEPSIA

Background-Studies have shown that an altered visceral perception thre shold plays a role in the pathogenesis of upper gastrointestinal tract symptoms in dyspeptic patients. However, it is not clear whether the compliance and adaptive relaxation of the proximal stomach contribute to the symptoms. Aims-To investigate whether abnormal relaxation or ad aptation of the proximal stomach during the interdigestive state and t he postprandial phase could explain the symptoms of functional dyspeps ia. Subjects-Twelve volunteers and 12 patients with dysmotility-like f unctional dyspepsia were included in the study. Methods-An electronic barostat was used to investigate adaptation to distension of the proxi mal stomach and accommodation in response to a liquid meal. Dyspeptic symptoms during distension and accommodation were assessed. Results-Wh en the subjects were in the fasting state, the pressure-volume curve s howed slightly higher compliance in the dyspeptic patients (p<0.05). P atients not only had a higher score for nausea, bloating, and pain but also the increase in nausea and pain scores with intragastric pressur e was higher than in volunteers (p<0.05). The increase in intragastric bag volume in response to a meal was significantly lower in patients (p<0.05). Both bloating and pain significantly increased in the patien ts (p<0.05), but not in the healthy volunteers. Conclusions-Patients w ith functional dyspepsia show slightly higher compliance to mechanical distension. Their visceral perception of mechanical stress is enhance d. In contrast with the balloon distension, relaxation after a meal wa s less. Therefore the postprandial symptoms cannot be explained fully by greater global tension in the stomach wall, as assessed by the baro stat technique. Visceral hypersensitivity plays a major role in the pa thogenesis of the symptoms.