Hi, I've never tried the calcium channel blockers, but Gabapentin works really well at blocking out attacks. Its an anti-convulsant. U could ask your doctor if u could try taking it. I've never had an ERCP done bc i have sphincter of oddi type 3, but this pill really works on the pain
How long ago was the ERCP?
In some cases the spasms can be tamped down by the use of some anti-spasm meds, or the use of specific calcium channel blockers.