RESPONSE OF GASTRIC FUNDUS TO RECTAL DISTENSION IN HEALTHY-PERSONS

We aimed to record fundic motor activity in man using the barostat to ascertain if fundic motility is affected by rectal distension. The dis tal ends of two barostat tubes were placed in the gastric fundus and r ectum in 10 healthy volunteers. The gastric bag was first inflated to a constant pressure level that recorded phasic motor activity as chang es in volume of the air-filled bag. Baseline motor activity was record ed before, during, and after a 15-min period of constant rectal disten sion that was clearly perceived by all subjects but was not painful. I n all subjects, continuous phasic volume changes, reflecting fundic mo tor activity, were recorded at a rate of 1-3/min. During rectal disten sion, a consistent change in mean contractile force of these phasic vo lume events was not detected; a decrease of more than 30% occurred in only three subjects. We conclude that fundic phasic volume changes are recordable by the barostat, but these are not substantially inhibited by rectal distension.