have you seen a dr? has ercp been sugested yet? if not cross that bridge when you come to and get medical evaluation first ... ERCP carries risks (like any other proceedure) and is not usually a first port of call in investigations. it is endoscopy under x-ray and can be used for further tests and treatment ie biospsy, stone removal, insertion of stent to drain the liver etc, i have had 3 difficult lots of ercp - and while they were not the nicest of proceedures to undergo they were of some use ... when i had my first ERCP i had a large stone obstruction in my bile duct and it was so large it was compressing a nerve and blocking off pain signals - the dr's kept telling me i was in pain - but i did not feel it!! the first one could not deal with the obstruction and the 2nd one was used to put a stent in to drain the liver and relieve the jaundice and let my liver recover - i was still in no pain in the area as the obstruction was still acting as a nerve block - so 8 weeks later when everything had calmed down and they managed to succesfully remove the obstruction i did feel pain again!! but apparently i had been in pain all along and it was not registering with my brain!! so no it did not cause pain, but allowed me to feel the pain i was supposed to be suffering!! as crampy738 says pain under left rib sounds like gallbladder!! get checked out.
Your pancreas is under your left rib not your right. It sounds like your gallbladder. Your doctor will probably schedule a HIDA scan to make sure you gallbladder is functioning properly or an ultrasound.
This could also be gallbladder related. I would get a diagnosis before going any further with this.