Constipation help!

Baby is now constipated I think. He normally doesn't have a BM for a couple days but he hasn't had one since Friday! He doesn't seem uncomfortable at all but has some serious gas. 
What can I do?? I have some Mommy's Bliss Constipation Ease but haven't tried it yet because it says for 6mo+ 
Thanks!! Ps. He is formula and breastfed.