Suggest An Alternative To Breast Milk For An Infant

My 15 months old daughter has loose motions 6 to 7 yestertday and 4 times today. Dr has prescribed zinc acetate oral suspension + omnix 100 + oflomac m forte. Dr advised no milk. He asked if d baby was on breast feeding and i answered yes ..but actually its been a month since d baby has left breast feedin. Please suggest alternate for milk.