Well it can be caused by intraabdominal pathology due to surgical procedure. Abscessus or intraabd. collection can occur even few months after surgery especially after the open surgery. If your pain is associated with fever
and muscle guarding then go to hospital and seek for help. But also your pain can be caused by bloating
and gas in your intestines. Whene you take drugs then huge amounbt of gas goes through intestines and causes cramps. So you can wait till your digestion stabilizes and see if pain s gonna be persistant or not.
Wish you good health.