Motor activity of the distal oesophagus and gastrooesophageal reflux.

The relationship between intraoesophageal pH value and motor activity of the lower oesophageal body and sphincter was investigated by simultaneous evaluation of intraluminal pressure and pH in 13 patients complaining of heartburn and regurgitation. One hundred and thirty one episodes of gastro-oesophageal reflux were recorded. One hundred and eighteen (90.1%) were preceded by a swallow (one to 12 seconds), 13 reflux episodes (9.9%) were not preceded by a swallow. Gastro-oesophageal refluxes preceded by swallow were accompanied by an equal number of normal and abnormal primary peristaltic sequences and, while recording at level of the lower oesophageal sphincter, occurred during inhibition of the sphincter. Frequency of abnormal primary peristalsis increased (p less than 0.01) during periods of low intraluminal pH (less than 5.0). An increase of at least 0.5 U in intraluminal pH occurred with 45.2% of normal primary peristalsis, 29.3% of abnormal primary peristalsis, 4.3% of secondary peristalsis, 3.5% of non-peristaltic contractions. The results of this study indicate that in patients with symptoms of reflux oesophagitis, gastro-oesophageal reflux appears to be related to swallow-induced lower oesophageal sphincter inhibition and not related to abnormal motor activity of the distal oesophageal body where an increased frequency of abnormal primary peristalsis appears to occur during low intraluminal pH and primary peristalsis appears to be the most important mechanism of oesophageal clearing.