My 14 year old son has recurring stomach discomfort, sometimes pain. When it happens about once every 2 months for a period of 2 days. He usually starts to feel unwell, pallor white, will throw up, becomes tired, may sleep a bit, then until the 2 ish days have passed will feel unwell, uncomfortable but does not lose his appetite. I am conceerned as it reoccurs. He has seen a GP. Thank you