Hi,
I was expecting that there should have been a history of cow's milk and formula feed (this too contains cow's milk protein) given to the baby. I feel that your baby is having cow's milk
protein allergy. Unusually babies grow out of this sort of allergy by 1 year of age.
My suggestions for you -
1. The mother should go off cow's milk protein completely. This means that you should avoid consumption of anything and everything related to cow's milk - like - milk/ curds/ ghee/ buttermilk/ chocolates/ biscuits/ ice creams etc.
Even while buying commercial food products, you need to see the ingredients and if they contain milk - do not consume them.
2. Feed your baby only exclusive breast feeds till 6 months of age and then start rice based feeds.
3. If this is followed scrupulously - the baby will stop having
diarrhoea in another 3-4 days and then start gaining weight too.
4. If you feel your feeds alone are inadequate for the baby, then Zerolac is the only option till 6 months ago.
I request you to keep me posted about the recovery of the baby and followup of the case.
Hope I have answered your query. Let me know if I can assist you further.