My Daughter Was On A Trip With Her Girl Scout

My daughter was on a trip with her girl scout troop today, she's 6 with be 7 in February. When she went to the bathroom and wiped, she said there was blood on the toilet paper. Pee only, not stool. She also went when she got home and said the same thing happened. She says it doesn't hurt tto pee and there is no blood in the toilet. Whatcould it be?