It is generally believed among physicians today that the effect of morphine on the intestine in the doses commonly used is to stop peristalsis and put the bowel at rest. This belief may be due to the results obtained in earlier experiments on isolated intestinal segments, on anesthetized animals or with improper doses of morphine. In the light of recent work it appears quite evident that the effect of morphine on the intestine is one of stimulation and not one of paralysis.
Those who have found paralysis of the small intestine after the administration of morphine are Legros and Onimus,1 Nothnagel,2 Leubuscher,3 Katsch,4 Meissner,5 Zunz and Gyorgy,6 Ohno7 and Garry.8 Those who have found that morphine stimulates the small intestine are Nasse,9 Pal,10 Popper,11 Trendelenburg,12 Behan,13 Macht,14 Uhlmann and Abelin,15 Baur,16 Tscherkess,17 Gordonoff,18
ORR TG, CARLSON HE. EFFECT OF MORPHINE ON THE MOVEMENTS OF THE SMALL INTESTINE AND SPHINCTER MUSCLES. Arch Surg. 1933;27(2):296-305. doi:10.1001/archsurg.1933.01170080072004