Lower Left abdominal Pain, ongoing..

Hi,
Hope I am posting in the right place.. I am suffering from a lower left abdominal Pain, it started Months ago. I did a colonscopy and as per the doctor, the colon is "innocent" from such pain. I went with the assumption that this is muscle related pain. Tried Muscle relaxants but with no success. I tried to associate the pain with medecines I take (I take Migrain Prophylaxes), but didn't succeed as well.

In General, the pain is not very sharp, but it is annoying, preventing me from exercising. it is kind of continous pain, persisting. It goes out only while sleeping.

Thanks a lot for reading,