Cramps can be due to gas or a blockage or ileus. Don’t be so quick to blame the morphine. That being said taking too much morphine gave me an ileus and yes an ileus will cause bad cramps at least until you start vomiting due to what can’t go down must come up. Then comes the NG tube. Gas when peristalsis hasn’t resumed can cause cramps and once peristalsis returns can be alleviated.