When did you guys first feed your baby other than formula/breastmilk? Everyone on my facebook is…

When did you guys first feed your baby other than formula/breastmilk? Everyone on my facebook is feeding their babies at like 3 months! I fed my first son at 5 months and had to see a GI because it messed up his belly so bad. The specialist told me theres just nothing good to come from it but the pediatrician told me to go ahead! So now I believe we will wait till 6 full months but goodness!