Responses to gastric distension in functional dyspepsia

Background-Studies have shown that an altered visceral perception threshold 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 adaptation of the proximal stomach during the interdigestive state and the postprandial phase could explain the symptoms of functional dyspepsia. Subjects-Twelve volunteers and 12 patients with dysmotility-like functional dyspepsia were included in the study. Methods-An electronic barostat was used to investigate adaptation to distension of the proximal stomach and accommodation in response to a liquid meal. Dyspeptic symptoms during distension and accommodation were assessed. Results-When the subjects were in the fasting state, the pressure-volume curve showed slightly higher compliance in the dyspeptic patients (p<0.05). Patients not only had a higher score for nausea, bloating, and pain but also the increase in nausea and pain scores with intragastric pressure 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 patients (p<0.05), but not in the healthy volunteers. Conclusions-Patients with functional dyspepsia show slightly higher compliance to mechanical distension. Their visceral perception of mechanical stress is enhanced. In contrast with the balloon distension, relaxation after a meal was less. Therefore the postprandial symptoms cannot be explained fully by greater global tension in the stomach wall, as assessed by the barostat technique. Visceral hypersensitivity plays a major role in the pathogenesis of the symptoms.