2 days without pooping

hello mommies. My Lo is 4Months old. Is it normal sa baby na hindi mag poop for almost 2 days? he is formula fed. We change his milk from Enfamil to Similac. March 24 we use suppository because dipa sya nag poop non and pang 2 days na and after lagyan ng suppository nakapag poop na sya but yesterday until now dipa sya nag poop ulit. please help. thankyou