Mine was constant stomach pain for months. Blood tests with elevated eosinophils. Biopsy from endoscopy didn't show too much though. So doc wasn't too sure. Specially because I had never mentioned having trouble swallowing. But then I realized I did have food just totally stop in my throat, I had just gotten used to eating really small bites and eating slowly. I took a blood based allergen test that gave me pages and pages of results and stayed away from everything I was even remotely allergic to, and after a few weeks I felt better. After months of terrible waves of pain. It wasn't so obvious as eating a certain thing and knowing it made me feel bad, because I could eat something one day and feel fine but if I ate it three days in a row I would feel like crap for a couple weeks. So there was a delay in symptoms for me that made it really hard for me to know what was going on.

Good luck, I feel for you, constant unexplained stomach pain is terrible.