1.   Several studies have shown the association of reflux oesophagitis with lower oesophageal sphincter dysfunction and impaired oesophageal peristalsis.

2.   Acid clearance time is a useful parameter of impaired oesophageal motor function.

3.   We speculated therefore that oesophageal sensitivity to acid would be reduced in PSS patients with impaired oesophageal peristalsis.

4.   Our aims in this study were to assess in PSS patients, with or without impaired oesophageal peristalsis, acid clearance by the oesophagus and oesophageal sensitivity to acid.

5.   Acid clearance time is a useful index of impaired oesophageal motor function.