Jill of Kitchen Fun with My Three Sons is now potty training her third child. She made this cute and tasty snack to encourage him. To make your own, all you need is a banana, a pretzel stick and chocolate chips.
Or you could use chocolate syrup, I suppose. But if you need to, then maybe it's time to back off on the Miralax. As a veteran potty trainer, I'll tell you: finding that sweet spot between a toddler's total constipation and total diarrhea is very hard. I could go on at length, if you like.