Question

Lynsey
Hi, my 4 week old has become very fussy these past few days.  He seems to whimper and moan a lot when sleeping, his skin on his face has became really rough.  His poo has been a bit stringy but he has been sounding blocked up especially at night time.  He is formula fed and can go between 2.5 - 4 oz at each feed! Anyone any suggestions what could be going on?