I agree with Sqad, for what it's worth.
Only one surgeon where I work carries out an OTC(On Table Cholangiogram) as a matter of course.
As a result, he has a 100% success rate i.e. none of his patients ever have to come back for ERCP.
If stones are found during the OTC he removes them there and then via laparoscopic exploration of the bile duct.
Sadly, his colleagues do not perform OTC's as routine, despite the best efforts and encouragement of the surgeon who does. In truth, none have the skill sets to match the required procedure, bar the one.
ERCP delivers the required results, it's just an extra inconvenience for all that could and should have been sorted during the primary procedure.
Best of luck.