Hi Ronee,
I would have abdominal cramping and pain when i was on prednisone. It felt like my intestines where getting all tangled up inside because they were inflamed and didn't have anywhere else to go.
I no longer take prednisone and the only abdominal pain i experience now is my IBS and that is a different feeling.
Since they checked your kidneys maybe you should see and gastroendriologist(spelling

) and if nothing shows there a gynocologiest. Just don't give up.
A nurse once told me if it hurts and they can't find the problem, that doesn't mean a problem does not exist. Be persisted and try other options to find the problem.
Like when i had back pain. Doc checked kidneys,, and nothing,, xray showed nothing, i took myself to gastro, nothing,, gynocologist want to do exploritory surgery, i said no thanks cuz i heard of too many people ending up with hysterrectamies. Then I went to rheumy because i was also experiencing flu like symptoms and the internet when googled said rheumatologist.
It was the rheumy who discovered that i not only had lupus but i had 2 slipped disks in my back through an MRI. He said xrays would not have picked it up.
So Keep trying, pain is not in your head.
Good Luck