Spontaneous peristaltic activity in the oesophagus after imitated acid gastro-oesophageal reflux. A study in normal subjects.

Prolonged measurements of pH and peristalsis in the oesophagus do not enable quantitation of the reflux material. Eight healthy subjects underwent 12-h continuous pH and pressure recording in the oesophagus and, subsequently, recording of pH and spontaneous peristaltic activity after instillation of 0.1 N HCl. Volumes of 2.5, 5, 10, and 15 ml were instilled in the lower end of the oesophagus in randomized order. No relationship between volume and peristaltic activity could be demonstrated. A direct relationship between the change in pH after instillation and the peristaltic activity was demonstrated (r = 0.8052; p less than 0.001). The clearing efficiency was 0.3 pH units per peristaltic contraction. A similar relationship could be found between the change of pH during a spontaneous reflux episode and the following peristaltic activity (r = 0.5993; p less than 0.002). The clearing efficiency was 0.37 pH units per peristaltic contraction. It is concluded that low pH is the determining factor for eliciting oesophageal peristalsis.