Pooing

How often are your babies pooing a day? My 3 week old formula fed baby usually goes 1-3 times a day but since Saturday he has been 6/7 times a day and his poor bum is so sore. Just wondering if this is something to be concerned about, I’m waiting for the gp to call me today. He started new medication for a hemangioma from the children hospital on Fri but they’re adamant it’s a small dose and not related