Severe Left Upper Quadrant Pain, Epigastric Attack And Intolerance To Gluten. Are They Related?
The occasional LUQ pain is probably due to your GERD. It may have caused ulcerations by the stomach which is cause of pain. However radiating pain to right shoulder has a diagnosis of Pancreatitis. It can cause sharp epigastric pain radiating to the right shoulder. It is a first possibility due to lax sphincter of Oddi function and previous gall bladder calculi.
The important thing is that gluten insensitivity will not cause such symptoms . It is associated with diarrhea or weight loss.
If pain is severe and intolerable then you need to consult a board certified surgeon as soon as possible. Few investigations like ultrasonography and blood amylase test may be necessary depending on clinical examination.
Hope I have answered your query. If you have further concern please let me know.
Regards.