Hi. Welcome to JustAnswer. I am Dr Uzair.I am reviewing your post and will post back with your reply momentarily.
Sine you have been through all necessary testing for the problem and the results were normal. It does not seem to be anything of serious nature. Yes, you are right diet can be a factor especially if you eat fried, smoked, spicy food and smoking and alcohol adds to it. I would recommend you to get a stool routine examination and an ultrasound abdomen or an endoscopy to see if everything is normal from inside of the stomach. Nothing much to worry about. Avoid particular kind of foods i mentioned earlier, take lots of fluids and regular exercise can help. Stool examination would screen for parasites if any.
Hope this helps.
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