Billy Mays poop

When you take a poop and think you're finished, but your body's like "BUT WAIT, THERE'S MORE," similar to a Billy Mays infomercial.

Sometimes may manifest as a poop lasagna.

Person A: "You were in there for like 20 minutes and it reeks!"
Person B:"Sorry, I had a Billy Mays poop."
Person A: "Damn, those are the worst."