Ambulatory 23 hour recording of intraoesophageal pressures in normal volunteers: a propagation analysis from one proximal and two distal recording sites.

pH data were obtained from one level and pressure data from three levels in the oesophagus over 23 hours in 24 healthy volunteers, followed by automatic propagation analysis of motility data and analysis of time with pH less than 4. Apart from periods of meal ingestion, isolated pressure complexes were found more frequently in the distal than in the proximal oesophagus. This was especially common in the recumbent position at night. Most contractions of the proximal oesophagus were propagating. In the distal oesophagus were propagating. In the distal oesophagus propagating pressure waves were more frequent during the day than during the night and most frequent during meals. The state of consciousness rather than body position per se is important in determining the frequency of simultaneous contractions in the distal oesophagus.