i also have the same symptoms after my gb surgery which was 15 years ago, i also seeked medical help cause i was having the same symptoms i ended up having an under lying ulcer no noticable with testing but after being treated for this i was cured.
Read through this. Unfortunately, you're not the only one to experience this problem following GB surgery. You need to find an extremely good doc to work with - one who knows something about post-GB surgery problems. This problem (if that's what you're experiencing) is not easy to diagnose or handle, so it demands an excellent diagnostician: http://hopkins-gi.nts.jhu.edu/pages/latin/templates/index.cfm?pg=disease1&organ=3&disease=12&lang_id=1
Please don't give up in trying to find someone to work with you. You may have to contact one of the larger teaching hospitals in order to find someone knowledgeable about the problem.
It sound like you read my mind. I am 19 and have also had those same pains even after they removed my gallbladder. All I can tell you is you are not alone. And that doctors will never truly pay attention to you because you are young. I just think of the pains I have as phantom pains and just wait them out. My advice is, avoid fatty foods. It seems to help me. Also, your bile duck is still there, so it is probably still trying to produce bile and not having anywhere to put it.
After that ERCP you've felt better? Were any stones in removed gallbladder?