What Should I Do About Persistent Lower Left Abdominal Pain For Three Months While Colospa Retard Provided Only Partial Relief?

Hello Doctor, I m having a pain in the lower left side of abdominal from past three months Visited many doctors and took medication but the problem still persists. My ultrasound and urine test reports are normal. Now lately I m being treated by another Doctor and he had proscribed Colospa Retard capsule twice a day for 7 days. Ater completing the course I did get a little Relief but the pain is still there but milder. When I told the same to my Doctor he suggested to continue Colospa Retard for one month twice a day. Now it s almost 15 days since I have been teking colospa retard twice daily but the pain keeps coming again. Now regarding the same I will like to have your opinion. Regards