This is very well said. I will comment however that not all allergies are immediate. Without getting too technical, some allergies are quick and easy to recognize, others are subtle and can present with any multitude of symptoms (skin rash, headache, runny nose, etc.). I would visit a doctor who deals with food sensitivities, like a licensed naturopathic physician. They should run the proper allergy and parasite tests.
To the OP: prilosec will not cure ulcers. It is a band-aid treatment that will have no positive effect on the disease process, but might make you feel better.
ulcers make sense (kind of). my wife had them, and she took protonix (or something like that) and changed her diet and eventually they went away.
It's very rare that its a sharp pain, though it has happened on occassion. It's mainly just a dull/bloated pain, typically after I eat. It kind of feels like my stomach is a bag full of rocks. If I don't eat anything, then typically there is very little pain - which is the biggest reason I've lost weight. I've cut my beer intake to 1/10th (hell...i can't remember the last time I got drunk - oh wait...yeah I can...about 2 weeks ago), and I just don't eat anywhere near what I used to because I don't like feeling like crap...I just don't know why ulcers would cause the squirts and lightheadness. That was the most frightening symptom...at its worst (probably a little over a week ago)...I was extremely lightheaded, and my face would tingle. I thought I was having a stroke or something...