Hi, My baby boy, now 1 month 21 days old has been on 70% formula feed and 30% on expressed breast milk. Formula feed used is Aptamil Gold Stage 1 but recently we are seeing he is having colic, gas issues. We have heard this formula is hard to digest and can cause gas and digestion issues. We want to switch to Similac Total Comfort or Similac Plus which are advertised as easier to digest. Please advise.