Ahhh, ang diarrhea at fever talaga nakakagulat, praying for your baby na mabilis gumaling! So pag switch ng formula milk, common lang na makikita mo is changes sa poops (pwedeng mas matigal o mas mabilis mag-adjust), slight constipation or looseness for a few days, at minsan may pagbabago sa appetite. Pero since ang pedia mo na ang nag-prescribe ng specific formula dahil sa gastroenteritis, siya na ang best guide mo, she'll know what's gentlest for baby's tummy right now. A few of us moms have noticed na ang transition takes around 3-7 days usually, so don't worry kung hindi agad smooth, pero keep monitoring closely and report back sa pedia kung may concerning changes. Sending healing hugs sa baby mo!