This is Dr Basu, Experienced Specialist.
I am here to address your concerns and provide great service.
I understand your concerns.
So far you did have all the relevant tests which seem to be normal per you.
So anything serious in the kidneys or other relevant organs is unlikely.
However, more common explanation can be muscle spasm and nerve related problem in the spine.
That will not show up in these tests.
Nerve compression in the lumbar spine due to the herniated disc can cause these symptoms.
That can be checked by a MRI scan of the spine if needed.
You will likely benefit from adequate analgesia with meloxicam, a muscle relaxant baclofen and physical therapy
in that case.
Have you tried anything for the pain?
Thank you for sharing your concerns with us today. If you have any additional questions or need further clarifications, please do not hesitate to ask. I am here to answer them. I wish you good health. Regards, ***** *****