To clarify: that article is about "functional gastrointestinal symptoms", which may be or not related to fructose malabsorption. The term "functional" disorder in medicine is used when no underlying organic/biochemical disorder can be identified. From what I understand now about FM, this is a distinct disorder (deficiency of fructose-transporting protein GLUT-5) and not a functional disorder (IBS). In the article, they try to cover the diet for both.
Despite the explanation about sucrose, they still recommend in the same article:
"Limitation of dietary fructose load (in the form of free fructose or sucrose) at any one meal;"