I think your doc's comment about the hole was unwarranted. But, be that as it may, was he referring to the fact that he cut the sphincter of Oddi, in other words did a sphincterotomy? And if so, did he stent you afterwards, and do you still have that stent in place?
If a sphincterotomy was done, it was to allow the sphincter (a muscular opening) to relax and reduce the pressure in the common bile duct. As that cut heals, hopefully it will NOT scar a lot since you really want that muscle to regain it's function - contraction - and scar tissue with not allow things to contract properly.
I'm assuming that you've already had your gallbaldder removed? Have you asked the doctor to check your liver and pancreatic enzyme levels? That should be done because the ERCP and any other procedure can both help, or it can also cause other problems such as a backup of bile toward the liver. It can also result in a backup of bile into the pancreas and cause of pancreatic problems - so enzymes levels NEED to be monitored.
The pain could be due to low level pancreatitis and if that's going on, you need to know. And you need to follow a diet to try to retard the damage pancreatitis can do.