My boyfriend has a fructose allergy he has had it since he was a kid is there any medicine out there that can help?

Allergy / intoleranc: I have never heard of a fructose allergy but there are many folks that are born without the enzyme in their gut that allows them to digest fructose. Like the better known lactose intolerance, this means if you eat fruit or drink juices with fructose you get cramping and gas.Avoidance is the main way to avoid symptoms. It is not common enough that the enzyme would be available.