DS is 15 months, not yet walking. We did a very part time ec when he was younger, and I'd sometimes catch a pee or poop. Now, he tends to poop during breakfast, and I sign potty to him when I notice, and then go change him. Recently he pooped and then signed potty to me. I'd love to catch him before he goes, so I can get him out of his seat and take him to the potty--did I mention he HATES diaper changes?--before we have to change a poopy diaper. Suggestions?