In a double-blind crossover study, lower oesophageal sphincter pressure (LOSP) and distal oesophageal motility were studied in eight healthy volunteers following a single intravenous dose of omeprazole or placebo. Lower oesophageal sphincter pressure was determined before and at intervals up to 120 min after intravenous administration of 40 mg omeprazole or placebo. No effects on LOSP or distal oesophageal motility were observed.