How do i shake off anorexia label

I am not now nor have i ever been anorexic yet people still think i suffer from anorexia. Ive always been very thin and used to be slightly underwieght. Now at 15 im a healthy 8 st 4lb (56 kilos), last year we found out i have coeliac disease which was stopping me being able to put on weight as quickly as others, even so i still get comments like "shes annorexic" and "you never eat enough, you need to put weight on" . No matter what i do i cant get people to listen to me, even my freinds sometimes comment on my weight, telling me im way to skinny. Addmitedly last year you could see my ribs but now they are almost invisible.

Anyone else get this?