Alternate milk

FTM here . My baby boy is turning 3 months tomprrow. Bottle feed po sya. S26 Gold milk nya before and when he reached 2 months naging watery yung poop nya so I switched to Bonna and naging normal ang poop nya. My question is, pwede ko ba e alternate ang Bonna at S26 sa pagpapadede sa kanya?? Sayang po kasi yung milk na S26 mero pa akoang 3 boxes ng tig 1.8kg and wala naman po gumagamit neto samin. 😔 please help sa may na expereience na and also advised ng pedia