Engelsk definition
Digestive system disorder where a particular food irritates the digestive tract or cannot be properly digested (i.e., due to a lack of a digestive enzyme). It differs from FOOD HYPERSENSITIVITY which is an immune system disorder, usually due to specific proteins in food. http://my.clevelandclinic.org/health/articles/problem-foods-is-it-an-allergy-or-intolerance.