Baby not pooping??

Google told me it's normal for a baby to go 7-10 days without pooping when they're breastfed but that doesn't seem right to me. For the past 2 weeks since babe hit 6 weeks old he's only been going like once a week and he is SO uncomfortable. He pushes till he's red and screaming to only get out a little fart, and he really can't poop unless I intervene and take his rectal temp and then it flows out like a ton was stuck in there 🙁 He's so uncomfortable, is this really normal? And is there anything I can do to help him go on his own so I don't have to keep sticking a thermometer up his little bum every other day? 🙁 I feel so bad!