Should the baby poop be inconsistent like different colour, often pooping within hrs apart after changing diaper then get it change to other brand like similac, dulex/dumex, nan optipro, etc. You can buy in small tin and see if there's poop changes. Having green/yellow with watery kind like poop perhaps your little one not use to the formula. However, it can also mean that they are lactose intolerant hence they need to change.