S.N.
I, too, agree that it is probably an issue with not thinking to stop playing long enough to go pooop. Also, though, it might be the differences in diet that we often have in the summer months. Perhaps more fruit is being consumed than normal. Or the juice and other sugary drink intake is higher, due to more thirst. Not sure what the protocol for that sort of thing is, in your home. But, anyway, the increase in juice, sugars, and fruits could be causing looser bowels. And, if this is the case, she might not feel the urge until it's urgent.
As a method of handling the problem, I suggest continually having her clean up the mess with her own little hands. Teach her the proper method for hand washing the underwear, and such. If this is an issue with her not wanting to interupt playtime to go potty, then it won't take her long to realize that going in her pants will take more playtime away than going on the toilet. Some might say that she's too young to handle that kind of clean-up. But, she's not. My son was a preoblem toilet-trainer. At the suggestion of his pediatrician, we gave this a try, and it worked. Oh, his results from cleaning the pants were not as good as mine would be. But, he did it, even though he was not happy about it. And, now, he never seems to have a problem in that department, at all.
