I've been out of town for work a lot lately... in West Virginia last week and in Alabama this week. While I was gone most recently, Todd was giving Mercer a bath & he pooped in the tub. Todd drained the tub / put Mercer on the toilet / and told him that this is where he is supposed to poop. And... Mercer did! Todd said he made a big deal about it, let him flush & wash it down, and gave him a fruit juice popsicle afterward to encourage him to poop in the toilet more often.
The next day, Mercer had to stay home sick (croup-y cough & wheezing). Todd stayed home with him and Mercer said he had to go to the potty. Todd put him on the toilet... and he pooped in there again! Woo hoo!
A couple of other things to note - Mercer is counting now very well to 5. He's also becoming interested in letters. While scribbling one day he kept saying "T" "letter T." (but it was just scribbles). He picked up a puzzle piece in the shape of a "d" and identified the correct letter, amazingly. (He also said "d" when we picked up other letters too, so we're not quite sure what he's getting / what he's not... but it's still interesting.)