According to history, probably Baby has some dehydration (irritable and not very active). Most of the time diarrhoea in children remains for 5-6 days.
W H O ORS and zinc syp plus frequent feeding are main treatment options.
Next Steps
I think continue breastfeed and other like curd or khichdi especially rice based.
ORS but reconstitute it in proper way.
Watch for urine out put
Is there presence of blood in stool .
Get well soon