You should be investigated.
Pain to the Left side of the abdomen can be mostly due to Ureteric stone.
It will be confirmed by Ultrasound
It is not due to constipation
The drugs that you have mentioned do not cause abdominal pain
Please consult your doctor and get an Ultrasound abdomen.
If you come back with Ultrasound report, I will clarify further.
If it is normal, then it could be musculo skeletal pain.
Nothing to worry.
Wish you good health.