I had kidney stones too that were too small and expected to pass. The pain was immense. The ER told me I needed to see a specialist but I couldn't get an appt. for at least 6 weeks. The ER put me on Viagra (I am a woman) but told me not ony is Viagra used for ED but it increases the diameter of the ureters helping the stones to pass. Eventually they did.

Fast forward several months, I went to see a new neurologist to rule out MS. As I gave him my history, he told me that my kidney stones were most likely caused by the Topamax I was taking for my crps. Kidney stones are a possible side effect of Topamax.

Discontinued the Topamax and haven't had any stone since.

By chance are you on Topamax for your crps?