The aim of the present study was to measure the amplitude, the duration, and the velocity of the peristaltic pressure wave in the lower part of the oesophagus in the basal state and at different time intervals after oral intake of 10 and 20 mg metoclopramide. In addition, gastro-oesophageal sphincter pressure was measured in the basal state and 90 min after the intake of metoclopramide. The pressure studies were carried out in eight healthy subjects, using a pressure probe consisting of two open-tip polyethylene catheters that were fed by a capillary tubular system and connected to external pressure transducers. Sphincter pressure was measured (intermittent withdrawal), and the probe was positioned with the distal opening 5 cm orally to the sphincter. Dry and wet (bolus, 5 ml of water) swallows were made in randomized order in the basal state and at the time intervals after the intake of metoclopramide. Finally, the sphincter pressure measurement was repeated. No differences were seen with regard to the peristaltic activity: amplitude, duration, or velocity. Sphincter pressure rose from 12 to 19 mmHg after 10 mg (p less than 0.05) and from 13 to 20 mmHg after 20 mg metoclopramide (p less than 0.05). There were no significant differences between basal values and the response to 10 or 20 mg metoclopramide.