For the first four weeks, my LO was getting almost exclusively breast milk. He was pooping several times a day. Since then, I have been transitioning him to formula.
Starting this week (week 6), he has gotten more formula than breast milk. I still plan on feeding him some breast milk until I am ready to be done pumping, but for now he is getting about 10-12 oz's per day and being feed formula for the rest. I think the BM poops have stopped. Yesterday he had one dark liquid-y poop, and so far nothing today. I am giving him Enfimil Gentalease formula. It's probably too early for me to worry, but I do.

When did you get worried about your LO's sudden lack of pooping? How many times does your mostly or exclusively formula feed baby poop? If s/he was having troubles pooping, what did you do?