My Boyfriend Is 30 Years Old For Two Years He

my boyfriend is 30 years old for two years he had a pain in the lower part of his front,he says that its not pain that hurts but it always there.All day everyday he just can't stand it any more,we have been to the emergency room to many times,we have been too many clinics and blood work and we get the same answer,its nothing I told him to start looking for a specialist I think he need to see a gastroenterology something different.its on the left side-in front like where the appendices would be