My son is experiencing extreme gas and is very uncomfortable, not sleeping well, constipated. i am currently breastfeeding and formula. i am using aptamil advanced, his stomach getsrock hard, should i put him on similac or s26 to help?

Hello, I am not sure how old your son is because that may be helpful in making a suggestion. However doing more of breastfeeding may be more helpful if there is adequate flow if not the mother should increase her liquid intake so she could get a better flow. The breast milk is better suited to digestion and giving water to the baby may also help.

Switching him to the formulas you suggest is not going to help. They are still cow's milk protein and lactose containing. IF you want to try a different formula, I suggest a soy based formula or an "elemental formula" such as Nutramigen or Alimentum which are very easy to digest. Also suggest you take a look at breast feeding mom's diet and keep it low lactose and avoid cruciferous vegetables.