Is switching formula milk of a toddler can cause diarrhea?

Sino na po nakatry magswitch from Nan HW 3 to Nido Junior? (My baby switched from nan hw 3 to nido junior. 1st and 2nd day is okay. When its 3rd and 4th day, she pooped 3x then its consistency is runny. As in watery. Im wondering kung normal lang po ba kasi naninibago pa tiyan niya sa milk or diarrhea na ba. Thanks for sharing your advise mommies. Ill appreciate your comments.)