After a week or so of not pooping you should give the frog a soak in 80 degree treated water. If your frog stresses easily you can gently place your frog in its water dish. This will encourage your frog to poop. As for aestivation, as long as your temps and humidity are correct your frog should not aestivate. Now with winter approaching your frog might naturally slow down. Your frog dug down because that's what pacman frogs like to do. Make sure you have just enough eco earth so that the frog can completely cover himself, but not deep enough where he can reallt dig down. Just leave the frog be, it will come up when its hungry.