My twin babies(girl and boy), having constipation for an month, we started solids a month ago (rice porridge and ragi porridge and apple) they started to have poop in black(solid texture) first and followed by yellow normal poop. They were active and having aptamil milk. And they just entered 6 month last week. I was informed black poop is blood leakage. Is thst true. Because both my babies having the same issue first time they will have black followed yellow color. Attached image. Please help with my question. Was very worried