What is a pancreatic hole?

my son of 12yrs has been complaining of nausea stomache pain and has been intermitantly unwell for a couple of weeks. i thought it may have just been the water as we had just mooved and he had only ever drunk tank water. but an ultrasound has shown he has a hole in his pancreas .apparently this is very rare . What are the symptoms? how did he get it? is it dangerous? Does it need to be treated?