5-HIAA elevated

Hello, I'm a 34 yo man with GERD symptoms and frequent jabbing pains in throughout the abdominal area.  I also suffer from palpitations due to anxiety and panic attacks.  

My primary care doc ordered a 24 hour HIAA test and it came back elevated 14.8 mg.

I am really hoping this is a false positive result, but can't see the doctor till next week.  I know that certain foods (bananas, walnuts, tomatoes) can cause a false positive, but how much would you need to eat to get an elevated result?

Is there anything else that could cause an abnormal reading?

I am taking Coumadin (DVT + Factor V Leiden), atenelol (small dose for palpitations and positive tilt test) and Protonix (for reflux)