Hello everyone. I apologize in advance for the photo. ?? Mommies, my s…

Hello everyone. I apologize in advance for the photo. ?? Mommies, my son's stool has been like this for the past three days. (I will attach the photo in the comments). What could be the reason? He only poops once a day. Previously, he would poop 3-4 times a day. We are on mixed feeding. In a day, we give him Nestomol 60mg per 2-3 times. He is not bothered by anything and is as calm as before.