Hi,
Welcome to health care magic,
Acute
diarrhea in 1 year old baby might be suggestive of intestinal infection,mostly due to
rotavirus or amebic /mixed/ bacterial infection.
Loose motion can also be a known complication with bottle feed if the bottle is not sterilized properly before each feed.
I would like to advise you to maintain the fluid intake of the baby by supplementing with
ORS and keep watch on the urine output.
As you siad loose motions has stopped now by giving zerolac then you can give normal milk or formula milk (similac which you give) whichever you are giving.
In case If diarrhea occurs again,then kindly get your stools checked, to detect the causative organism.
Your baby will need some specific drugs (according to the causative organism) like Metranidazole,antibiotic like
Norfloxacin, antispsmodic drugs to control the pain will cure.
Please consult a pediatric doctor for specific prescription.
Thanks and regards,