Peristalsis in the isolated guinea-pig ileum during opiate withdrawal.

Naloxone enhances peristalsis in isolated intestinal segments from morphine-dependent guinea-pigs to a greater degree than in naive preparations. These data suggest that a peripheral mechanism may be involved in the expression of opiate withdrawal in the small intestine, and indicate that the action of this mechanism leads, at least in vitro, to an increase in the number of peristaltic waves.