1. what can use relief constipation on my baby she's 2months old & feeding on formula (s26 gold). 2. what age is suitable to pierce baby's ears?

Ask her doctor first: Call pediatrician. If a 2 month-old has been pushing when pooping, or pooping formed poops (but is still eating fine, not distended in the tummy, and is otherwise being happy), some parents try using half a glycerin suppository. After rubbing the surface of the suppository smooth, it should go in gradually. If constipation is ongoing or if suppository didn't work, there may be a bigger problem.

Piercing age: The piercing may be completed in early infancy, but waiting until the baby is sitting or walking allows the immune system to better react to possible infection which is a possible complication. Discuss formula feedings with your Pediatrician, but the other answer from HT describes that pattern may be normal.