In early November, we jumped right into a potty training intervention for Elliot. Straight to big boy undies, too. He wasn't balking at the idea, but he wasn't showing much interest, either. By the end of day 1, we'd caught 5 pees and lost 1 on the couch. Day 2 he went to daycare, but there were 2 accidents before we got out of the house that morning and 2 more while at daycare. Day 3 was pretty good - but he was in a pull-up due to errands and a new babysitter. Day 4 was another daycare day and there were 4 accidents. And an elusive poop on the toilet! Poor boy had been holding it since day 1 and was pretty sore.
By day 5, he was starting to tell us when he needed to go pee. And then he pretty much became a bladder master - during awake hours, that is. He's still in a diaper at night and a pull-up at nap time.
Catching a poop is another issue entirely. There will be days where it seems that every 10 minutes he's frantically saying he needs to poop and we race to the potty or toilet and he sits there and tenses up and sucks in for anywhere from 10 seconds to 20 minutes and nothing comes out. And he'll do this for daaaaays until he has an "accident" in his underwear. And then he slyly says "Ohhhh, we missed it." Lather. Rinse. Repeat. Repeat. Repeat.
It's a work in progress - there's been much work and much progress. And it can only improve with age. I hope!