breastfed baby

Jasmine • Mother of 2! #momofboys Instagram: jasroc3
My son is 5w today. I'm currently pumping and bottle feeding. The last few days he hasn't pooped much, and when he does it's not a lot. It's obviously making him uncomfortable and kind of fussy, so maybe he's gassy too idk. Any ideas on what I can do to get the bowel movements back normal? I've tried the laying him on my lap and rubbing his back, that helped a little with the gas but not much. 
Anything helps! Thank you..