Effect of opiates on gastroduodenal motility following surgical operation.

Following surgical operations, opiate analgesics are widely used to control pain. This situation was used to investigate patterns of human gastroduodenal motility and the effect of opiate analgesics on this motility during the early postoperative period. Gastric contractions were absent for 6--12 hr following surgery in most patients, while there was no inhibition of duodenal contractions in any patient. Opiate administration had no effect on either the time of return of gastric contractions or on gastric motility once contractions had returned during the period of study. Duodenal contractility, however, was markedly increased by opiate administration (P less than 0.001) and took the form of frequent bursts of phase III activity of the interdigestive migrating complex (IDMC), but with a reduction in the proportion of phase II activity.