Abstract

The motor responses of the small intestine to intraluminal distension were studied proximal and distal to an inflatable balloon in 13 normal volunteers. During fasting, distension rapidly induced a persistent localised inhibition of distal contractile activity with a small proximal increase. Proximally, phase III activity was unaffected during distension but its propagation across and appearance below the balloon was inhibited. Upon deflating the balloon a normal motor pattern rapidly returned. Similar changes were observed during distension in the fed state. The changes in the motor pattern resemble those of the intrinsically mediated 'peristaltic reflex', studied in animals, and suggest that in man the response to balloon distension may also be mediated through an intrinsic mechanism. A patient with a visceral neuropathy, studied in a similar manner, had no inhibition of distal motor activity during distension, suggesting a functional defect of the enteric nerves. Further observations of the motor responses to distension in similar patients seem indicated to determine the usefulness of this technique for evaluating enteric nervous system function when an abnormality is suspected.