Suggest keeping a daily diary of everything you eat and drink. Include how it was prepared ( fried, baked, grilled, steamed) and what condiments and spices used ( butter, salt etc...). Include your activities, exercise, etc.. Also include the times of occurance, length of duration, and the intensity of the pain on a scale of 1-10, 10 being the worse pain you ever experienced. This will help your MD with is diagnosis - don't forget to take this info with you.
Also ask you PMD for a full blood workup again. And just because your above mentioned medical problems aren't in the past or family history, doesn't necessarily mean they aren't occurring now.
Have you consulted a specialist? Frequently items cannot be found until further testing is down. You did not mention if you have had any tests. Hope you can find out what is wrong.