7 week old trouble popping?

Asia • Mom of three 💙J Aug '08, 💜 E Aug '14, 💙 T Dec' 19. Wife 💍and eternal partner since Sept '10.

My breastfed son is still pooping regularly not as much as before but still more than once or twice a day. However for the past few weeks I've realized a few times he gets fussy and seems to be pooping, usually he poops sometimes he doesn't. However he seems to be having some serious issues. It's pretty much the only time he gets fussy. What could this be?