My DD (11) has it. She also hides her undies or throws them out because she is so embarrassed. No amount of reassuring her helps, I can understand why!
They can't feel it coming because everything has stretched and the nerve ending lose sensation. Laxatives need to be used for years, DD had them for 2 years, we were told she was ok and to go off them, 7 months later we were back to square 1, and are now in the 9th month of a new course of laxatives.