Pains you experience may be called "hunger pains". Duodenal ulcer is one typical reason, releaving of pain after eating and heartburn also both speak for it. If it is ulcer, you'd have some blood in the stool, not necessary seen with a naked eye, but with a (1) hemoccult stool test. Another test you might want to have is a (2) breath test for H. pylori - this causes ulcers and heart burn. (3) X-ray with barium (also called upper GI) may show ulcerations in duodenum or further in the small intestine. (4) Capsule endoscopy would clearly show any inflammation or ulcers.
You can have tests one after one. I think you should confirm/rule out this duodenal ulcer first.
I don't think this is a gallbladder pain. This would be only on the right side and would appear *after the meal. *Pancreatic pain or intestinal spasm would also more likely occur after eating.
You can also search for "hunger pain" to see, if something other resembles your pain.
There are no other symptoms I can think of but I think that eating something does make the pain go away faster than if I dont eat. It still takes a while after eating though for the pain to go. Sometimes the pain starts with some slight heartburn before it hurts in my stomach. I wouldn't say its a burning pain. More of a cramping pain. Not that I have been stabbed before but I would say it feels like someone is driving a BBQ skewer or a knife into me.
Few suggestions:
1. Duodenal ulcer. Worse on empty stomach, after acidic meal (fruits, vit C, wine, vinegar) or aspirin; pain may appear at night. Pain is relieved by eating or antacids. In Zollinger-Ellison syndrome these ulcers may appear deeper in the smal intestine, where they are not reached by the gastroscope. Barium x-ray or capsule endoscopy would show ulcerations. I doubt you would have this for 12 years though.
What kind of pain is it: burning or like a cramp? Any other symptom - black or bloody stool, bloating, constipation...?