My newborn always seems uncomfortable and is constantly fussing, pushing, tensing, grunting and turning bright red from trying so hard. It sounds like he's struggling to poop all of the time. I breastfeed so his poops are very liquidy. I don't see how he could be having trouble with it? It's affecting his sleep too. He will be laying there soundly for a bit and then will wake up struggling. :/
Do you burb him? My oldest would get like that when he had a burb stuck
Also you could try laying him over your thighs, being in that position would sometimes release gas -- whether it be a burp/fart.
Another thing, you could lay him on his back and move his legs in a bicycle motion. Then push his knees up into his tummy, then stretch them out flat for a few times.