What could happen if someone with anorexia overeats?

i am anorexic, and i also take laxatives to try to control my weight. once in a seldom while i will go out to dinner or to a family party and i will overeat (it really doesn't take much to make me full). afterwards i feel completely miserable. i can barely move and the next day my entire body feels beat up and bruised. what is happening with my body?