Hi. Thanks for your query. Noted the history and understood your concerns. Recurrent upset stomach with instigating factors known, nausea, vomiting, burping and such symptoms indicate the following: It can be either intolerance to something in the foods or beverages that you are taking and a keel observation can help you to pin-point the cause so that the causative agent is stopped and you will get alright. Or there can be recurrent Gastroenteritis. Whatever the cause you have to undergo the tests of blood and stool. Get an ultrasonography as the problem is for the last 4 weeks. Upper GI Endoscopy to see for any gastritis related problems. Clinical evaluation by your Doctor and appropriate correlation with the reports will give a proper diagnosis so that you can have proper management both preventive and therapeutic may be in the form of a PPI like Omeprazole, Domperidone antibiotics if there is any evidence of infection.