Poo accident

Tonight, Phoebe poo in her panty...she will usually tell me if she wants to go toilet but she didn't today and this poo accident happened twice this month. Well, I lost my cool and reprimanded her..Ya, I know accidents aren't the end of the world..but I have to clean up the mess especially the soiled clothes! I will have to remind her again tomorrow before she's off to school and I don't want that to happen again in class!