You don't need to do an endoscopy... Just tell him you'd like to get set up for a HIDA scan or Ultrasound for the gallblatter.
By your experiences , I can see that you and I share the same discomfort... that dull ache can be very persistant... Hopefully the foods you are eating aren't a lot of heavy foods like beef , deep fried , or creamy foods.
Go to the grocery store and load up on instant oatmeal , watermelon (fresh), cantelope , roasted chicken(peel skin) , fish , and lettuce , granola bars , and applesauce. Don't slam it down but eat some every hour.. You'll be better in a day or so. Stop the prilosec in my opinion.. that stuff has side effects like crazy.