I agree with CalGal - I suffer from SOD. You can try a the meds that CalGal referenced, however there's only a 50 percent chance of those working - just so you are aware. Also, there is another med you can add to the list to ask your doc about, it's an antidepressant called Elavil which is prescribed as a pain management tool. That along with a muscle relaxer called Levbid really helped me.
Elavil has a side effect of numbing your body's nerve endings, which increases your pain tolerance level. Levbid is a smooth muscle relaxer. Neither fixes the problem, but it can help to make life a lot more tolerable.
Most importantly, do research and find a GOOD doctor to help you manage your SOD. No one should touch you for an ERCP unless that doc has performed literally thousands of them. Some good centers for SOD are Indiana University, University of Minnesota, Univ of South Carolina Med Center, just to name a few. You can search and find published doctors who are extremely versed in SOD.
Good luck! I also agree with CalGal in that SOD is a very hard condition to fix and also live with. I'll be thinking of you.
Read through this: http://www.hopkins-gi.org/GDL_Disease.aspx?SS=&CurrentUDV=31&GDL_DC_ID=320F4EDD-0021-4952-83D7-8B0C67B47BFF&GDL_Disease_ID=7AB086B0-AB01-446E-B011-2E67CAFEF96D
Al, you might want to talk to the doc about using some anti-spasm meds, specific calcium channel blockers or nitroglycerin. They may be of help. The problem is if you really are experiencing SOD after removal of your gallbladder, the only way to handle the situation may be to go through an ERCP with manometry and measure the pressures in the common bile duct. If the pressures are raised, then the typical solution is to cut the muscular opening - the sphincter - at the duodenum. I hate to say that, but SOD is a very difficult condition to try to fix/handle.
Let me go get the link to a decent explanation of SOD and post it.