Hello, my 4 and half year old boy has a problem of vomiting after every second month and when he starts to vomit he has a fever. I took him to many doctors but they cannot diagnose him. This has been going on for almost 2 years. Now I do not know who to take my boy to. Can you please assist with advice? What could be the cause and who is the specialist who can help?

Start a diary that tracks where he goes and what he eats. This should be able to either form a pattern, IE every time he visits town XXXX he gets sick a week afterwards or after he eats Fava beans he gets sick, and you can go from there.