Neural and humoral factors in postoperative ileus

Two inhibitory mechanisms in the human colon which may contribute to postoperative ileus have been studied. Dopamine, a possible peripheral neurotransmitter, inhibited isolated colonic smooth muscle strips by a direct effect in longitudinal muscle and by a nerve‐mediated mechanism in circular muscle. Plasma motilin levels were suppressed pre‐ and peroperatively and elevation of levels postoperatively correlated with the return of normal motility and the severity of the operation.