Schultz Party of Four

I think there might be a probe in my future...
or perhaps you can solve the riddle for me?
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About a week ago I started having a mild stomach ache after lunch.
I realized on Saturday that the nausea feels like it can only be cured with more food.
By Tuesday I had to leave work in considerable pain after a Mexican lunch.
I also am getting intense hunger pains, like I'm starved at odd times.
Today I had salad and pizza and was extremely uncomfortable yet again after lunch.
However, the mystery is that my Chipotle dinner didn't irritate my stomach much at all.
It is upper abdominal pain, not lower, and comes in waves.
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What's with lunch? And what's with me?
This is not cool.
I see a doctor on Friday.
Stay tuned for the answer to this confusing riddle.
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[photo from Flikr]