Hi Kathy. I also have a sensative stomach and aggressive CRPS. Began with:motrin, naprosyn, darvocet, percocet, vicodin, valium then Kadian(a morphine sulfate) supposedly has a more even release of morphine which means it is less addictive but it really messed with my head and constipation, next was Oxycontin which wasnt as bad on my stomach or head but still foggy. Didnt control my pain or spread. Then put on methadone which found it doesnt bother my stomach like the other 2 and definately better on my thinking. I called it my miracle drug. My one Dr. who was into ketamine disagrees with using opiods but I am continuing on methadone and continuing to research. The problem i have found is we all react differently to different meds. Good luck. momof4