I don't know what to do

In the past week or more, Georgia has not successfully gone "#2" in the toilet. She has pooped in her panties or her diaper every time. It is a complete relapse--she was pooping in the toilet like a champ before this setback. It is not that she is hiding in a corner and pooping in her panties. She usually tells me that she needs to "try" (her phrase for going #2), but she is in the process of going when she tells me that, so by the time we make it to the toilet, she has pooped in her panties. This morning, she had a couple different false alarms, where she thought she had to go. I knew it was coming, but I still couldn't get her to the bathroom fast enough when she really started pooping. I am trying to encourage her to "run, run--hurry!" to the bathroom when she has to go, but this morning (and other times), she gets upset about the pooping, starts fussing (instead of running), doesn't hurry to the toilet, and poops in her panties. It is like, all of a sudden, she can't stop it. I don't know what to do, and I am very VERY frustrated right now. What do I do????