My son is 5.5 months old and wakes up 3-4 times at night. Will introducing solids help him sleep through the night?

Maybe this will work out for u as well. Have a routine for ur baby. Feed him more before going to bed. Monitor the feeding time and bed time. Let say bed time na pag 9pm dapat madami syang nadede bago matulog. Then after 4hrs khit di pa sya na gigising pa dedehin mo na ulit, another 4 hrs dede ulit. Para ung tulog nya dere derecho. O Kaya observe mo ilang oras ba sya bago magising after mo pa dedehin, from that ikaw mag set ng time Kung anong schedule ng dede nya. Wag mo na po antayin umiyak basta Alam mo na dapat ay nadede na sya pa dedehin mo na. Kasi pag inaantay mo na magising doon magsisimula na mamuyat sya sa Gabi. Make that a routine at hindi ka pupuyatin ni baby sa gabi.