Pain lower left abdomen. Of my pain.

I have started getting cramps or trigger like pain in my lower left abdominal area 20 days back... It happens mostly when in sitting posture. I performed sonography last week where a stone could be seen in lower left uretur. I consulted urologist for the same but he could not find any stone. As I was still in pain, urologist suggested me to get a CT scan done for abdomen and kub. CT scan reports were normal and urologist suggested I have nothing related to kub. Then I consulted gastro specialist. He performed colonoscopy. But even those reports are normal. Doctor has mentioned I have no issue with my stomach area. He has given me 2 tablets - mebiz sr and tryptomer 10mg. I have attached my repots can please check and let me know the possible reson of my pain.. thanks