Help! My leopard gecko is constipated! She has moss stuck in her butt!?

I use paper towel as substrate because I've heard that loose substrate can harm Leos but in their humid hide I have moss that I got from the pet store which I moisten everyother day. I think Yoshi was trying to strike at a cricket that may have ran in the humid hide but swallowed moss instead...it is sticking out of her butt and she is trying desperatly to pull it out. This is the first I'm seeing this happen and she is pale. Please help Yoshi! What do I do??