I can't guess your brother's age. However it is not normal for him to
have the kind of symptoms you describe.I was just curious why you
mention Crohn's disease.Is there a strong family history of samr?
Is your brother overweight
You have to worry about anorexia
and bulemia.But, if he is really
having problems keeping things down, he needs to have additional
tests that may include a good history,examination and blood work
and X-ray studies.He may need even an endoscopic exam of his
stomach.Sometimes,brain lesions(Tumors) can give same symptoms.
He needs close medical supervision.
Take him to a gastroenterologist who can do the right tests.
Wish your brother well.