3 week olds poos less frequent

[Lalarosex]

My baby is breastfed and his poos were 4-5 a day, yellow, stringy, seedy and often explosive!
the last 2 days they have become runnier and less textured. They are still yellow. He is only managing maybe 2 a day

He is getting plenty of wet nappies

should I be concerned by this?

Sounds absolutely normal to me. Their poo will change as they, and their digestive system mature.

As long as they have plenty of wet nappies and are bright and alert at times they'll be fine

As long as he continues with lots of wet nappies and everything else is normal I wouldn't be concerned at all. Babies poo less often as they age especially breastfed babies as breastmilk is very easily digestible so their bodies use up most of it. Some older breastfed babies only poo once a week!
My little one did several a day at first now she goes maybe once a day or every second day. She's 2 months old now