Thanks for the query.
Formula feeds, if they are not properly diluted, infections, colds, antibiotics, allergies, food
poisoning are some of the causes of loose motions in baby.
As everything other than increased frequency of stool is normal , nothing to worry and infection is less likely.
See a doctor if-
Child has
fever along with frequent motions, Throws up after every feed, Shows signs of
dehydration like, excessive thirst, dry tongue, sunken eyes and cries without shedding a tear, blood in the stool.
You can give him oral rehydration slution, probiotics, zinc.
Hope i helped you.