You might want to read the IBS 101 thread. There are a cluster of symptoms for an IBS diagnoses.
We can't tell you here.
What kind of doctor diagnosed you.
Have you had any tests?
there is no test for IBS, its diagnosed based on symptoms, but if IBS is what you have you don't want to take pain meds long term it will make it worse.
what tests have they done on you?
narcotic bowel syndrome
There is also another condition called chronic functional pain syndrome.