Hi Rosie,
I want to share a recent experience in case it might be of help. My daughter has RSD that we have been able to keep under control with hyperbarics ... that is until about three months ago when she started having terrible burning in her stomach that was not responding to these treatments. Last week she developed a stomach virus and ended up in the emergency room because of the horrible pain. When we left they gave her a medication, Bentyl, which is a drug used for irritable bowel. Surprisingly it stopped the burning pain that we had not been able to control for the past several months. My other daughter is a pharmacy student, and she said that this med works thru the sympathetic nervous system (often thought to be involved in RSD). Just thought you might ask your doc about this med if you have not already tried it.
Best wishes,
Jeanne