Warning: poopy diaper in pic

The past week whenever he pooped, it had black pepper looking specks in it. Doc thought maybe it's due to me drinking more cow milk lately. This was just a while ago. Looks like black clot looking clumps in it. Waiting on a call back from doctor about this and she got this photo. Has anyone ever seen this before? I know black can mean blood.

He's acting normal. No vomit and eating well. No fever as well

Update: he's not on solids yet