dog regurgitation

How to go through this object to my dog?
My years of age, a laboratory had been acting sick for the past 3 days or less. He had diarrhea, vomiting, regurgitation and lethargy. I made a vet appointment for today. But this morning I found a large (Size of a tea towel) piece of a braided rug on the floor. I'm sure he or vomit or poop out. He was covered with a brown / green slime and left the same color liquid stain on my carpet (yuck!). I wonder how you think the piece of carpet went through vomit or poop? Is acting like his old self. Not sure if I should cancel my appointment vet or not? Probably all the questions of my vet. However, I am just curious what the community has to say. Thank you.
I bet he threw up. Amazing what the dogs eat! Edit: Yes, of course your vet appointment. I thought that went without saying …
Mitral Regurgitation – Color Doppler Echocardiogram – Dog