AbstractMeasurements of the lower oesophageal sphincter pressure and gastric secretion were made in patients with dyspepsia but no reflux and in patients with a hiatus hernia and reflux in response to a near maximal dose of pentagastrin. Patients with hiatus hernia had lower resting sphincter pressures than those with dyspepsia. The magnitude of the pressure rise following pentagastrin was related to the resting tone of the sphincter. However, in terms of percentage increase over resting sphincteric pressure, patients with dyspepsia and patients with a hiatus hernia had similar responses.