Baby straining, going red faced but has soft poos

[Dolphin27]

Hi, my 3 week old son over the past few days has started to strain and go really red faced as if constipated. This is throughout the day not only when he is pooing, he is breastfed and has nice soft poos. I've read it could be part of his development learning to loosen his bowels, however wondering if anyone has any experience of this? He is started to get irritated by it and not settling as well, but dosent seem in pain.

He was born a month early and due date still wouldn't be for another week!!

Thanks for your help

Yes!!!!! I actually went to ask a GP about this yesterday (My 3rd attempt...). My little boy has struggled with this on and off (mostly on) since he was 8 days old. I was told he was learning to use his bowels and would grow out of it by 3 months. However he's 5 months now!!! He doesn't get quite so distressed as he used to but still struggles. I find sitting him upright sucking a dummy helps him (or breastfeeding).

However, I wonder if it's linked to other issues . He's been diagnosed with silent reflux, probably as a result of cmpa (cow's milk protein allergy). His poos are full of mucus. So I wonder if that's why he struggles to go. I've given up dairy and soy so will be interesting to see if he improves any further.
Please let me know if you find an answer as it has me mystified! :)