If it's in your internal organs (kidneys, digestive tract), you can try a smooth muscle relaxant like Nulev to relieve the pain. You can take it during the day. It won't make you drowsy
. If you think it may be muscular, or stress related, you could try regular muscle relaxants like Flexoril or Skelaxin at night. Suggest this to your Dr. and see where it gets you.
Also, do you do a lot of bending or lifting kids at work? You could be straining musces without realizing it.