Objective: To study disturbances of gastrointestinal motility and afferent (sensory) dysfunction in functional (unexplained) dyspepsia, and the interrelationships between motility and sensory dysfunction.
Methods: Twelve patients with functional dyspepsia and 12 controls matched for age and gender were studied. Intestinal perception thresholds were tested by a standardized stepwise distension procedure in the third portion of the duodenum with a barostat device. Small intestinal motility was measured with a low compliance perfusion system proximal and distal to the distending balloon.
Results: First perception of duodenal balloon distension occurred at significantly (p <0.01) lower pressures in patients (23 +/- 3 mm Hg, mean +/- SEM) than in healthy controls (31 +/- 3 mm Hg). Patients had a lower maximal intestinal pain tolerance than controls (31 +/- 2 mm Hg vs. 39 +/- 1 mm Hg, p <0.05). Duodenal distension inhibited intestinal motility distal to the distending balloon (peristaltic reflex) more often in health controls (11/12) than in patients with functional dyspepsia (5/12, p <0.05). These alterations of small intestinal motility occurred at pressure values below the perception thresholds, and disturbed motility responses were not associated with perception thresholds.
Conclusion: Disturbed peristaltic reflexes and decreased sensory thresholds for perception of intestinal sensations are prevalent but may be independent abnormalities in patients with unexplained dyspepsia.