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the investigations which were done very relevant and very informative to pick up all possibilities for your pain , as they have been negative , I would not advice you further new investigations,these symptoms could mean a diffuse non specific abdominal discomfort, as a mild hiatus hernia
was there 10 years ago ,I cannot think of any other possibilities for now, so do not worry
It would still be wise to cut down the alcohol consumption . This will help you.