Trimebutine meleate and metoclopramide increase small bowel motility. The present manometric study of the human normal interdigestive duodeno-jejunal motility demonstrated two different pharmacological effects in 15 healthy volunteers. Trimebutine constantly induced a premature phase 3 activity (0.81 +/- 0.4 min after a 100-mg intravenous injection) with patterns similar to spontaneous phase 3. Metoclopramide increased the motility index (contractile activity) during phase 2 without inducing a premature phase 3. No significant variations in plasma motilin concentration were noticed after either trimebutine or metoclopramide. The pancreatic polypeptide concentration rose significantly after metoclopramide injection.