Help baby poop concern

* went to the Drs on Monday as on Sunday by baby 6 months has black in his poop no on solids at all yet, she said id want to see if happened again would want to see it. Called today as there was a lot! In the poop compared to last time! And spoke to dr on call and said it's to do with reflux il prescribe medication stronger, didn't want to see nappy like woman before said or want to see him. I know I'm a worrying mother but don't feel it's normal
IMG_0719.JPG And seems conflicting info