best not to intro other food except milk for babies less than 6 months old, as their gut system isn't that developed yet. have you tried adding in probiotics? if your baby is mainly on breastmilk, you can use Vivomixx. https://s.shopee.sg/6fQDfUEMXY otherwise, if you're feeding formula milk mainly, you can feed your baby kindernurture. https://s.shopee.sg/LWA7ujnIf
try gripe water and probiotics. also exercise the legs and tummy. I wouldn't give juice at this age
Buy ridwind , recommended by pediatrician
Try bifibaby, from kids clinic
Strictly no. Probiotic