My cat ate a small piece of curling ribbon — should I be worried?

I've been in your shoes before--one of my cats got into an easter basket and ate some of the gr--I was told to watch for it in the pan...and if he started acting sick or stopped eating to bring him to the vet....also read online--if you see a piece hanging out of his rear---do not pull on it because it could be wrapped in intestines and will cut them if pulled on...