Left kidney pain symptoms and conditions

I have been taking Lisinopril, 10mg, for almost two months and even though my latest blood work does not appear to show any kidney or liver problems, I have developed a lower back pain that only hurts when I move from a sitting position to a standing position. Once I am standing the pain goes away. Is there anyone out there who has similar condition?

The only other medications I take is allopurinal for the gout and aspirin, 325mg, every morning. I am 69 years old and feel very good otherwise.