I agree with Lyn, go with your gut (no pun intended) instinct and get the GI work up. If that shows nothing which I pray it doesn't, than you may need an MRI or some other tests. Often when we have a disorder i.e. Anxiety, that is the first thing that comes to peoples mind.
Be your own patient advocate and never get into the rut of letting people poo poo you as just being too anxious, if your instinct is waving a red flag.
Take care and keep posting. My Father died of Pancreatic Cancer so I understand your thought pattern well.