Trouble with poops

I just posted this to my EC group:

I'm having trouble catching poops... The ones I *do* catch are either soon after a pee and then I get them b/c Elie (3.5 mos) doesn't quite seem done after peeing, so I leave him on to see if he has poop, or he has some gas first and I catch those. But lately, I often can tell he needs to poop (by feeling some rumbling in his tummy) only about a second or so before the poop comes out. Literally, I'll say, "I think he needs to poop" and then the poop comes before I can do anything. For pees, he'll often cry if I don't catch the early signals and can hold pee for quite a while now (maybe 15 mins) and will cry while I'm running to a place to pee him, but not with the poop... Is that common? Is it harder for him to control/hold the poop? Thoughts?