Eh, 4 hari x poo memang jadi stress kan! Dengan BF + solids baru, tummy dia still adapting pa. A few of us noticed baby jadi constipated when kita introduce makanan baru, try offer more water dalam sippy cup or suapkan puree fruits like prune or avocado dulu, then tengok lagi few days. Kalau sampai 1-2 minggu lagi x poo or baby nampak uncomfortable/tegang, better check with your paed kay, sometimes kena adjust solid intro sikit