All summer long i eat only food from local farmers market. if i go out of town and eat at even nice restaturants i get symptoms. is that foodborne illness?

What symptoms? : Depends on what your symptoms are. It could be travel related but not necessarily food borne or illness. If your diet changes when you travel, you may be exposed to something to which you are intolerant like gluten or lactose? Perhaps you have allergies? Stress or lack of sleep from travel and commitments? Exposure to contagious illness e.g. On airplanes? Many possibilities.