1.   Twenty three patients also had an acid clearance test before and after healing.

2.   They also had longer acid clearance times.

3.   The acid clearance test was performed using the technique originally described by Booth et al with some modifications.

4.   The acid clearance test failed to discriminate between patients and volunteers in the first group as it was grossly prolonged in most of the subjects.

5.   The acid clearance data presented here are from the second group of subjects.

6.   Median acid clearance times in both sitting and supine postures were significantly longer in patients than controls.

7.   There was no significant difference in the acid clearance times after healing of oesophagitis.

8.   Oesophageal transit and acid clearance have also been shown to be slower in these patients.

9.   The prolonged oesophageal acid exposure seen in patients with hiatus hernia is because of reduced acid clearance but it is only seen in patients with lower oesophageal sphincter deficiency.

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