POO-merr-ang. Noun. Primarily used in corporate office environments involving the distribution of poo. Not to be confused with poo that rolls uphill or downhill, the poomerang is poo that is sent but inevitably returns at much higher velocity to its original vendor.

After you have a bowel movement, and you think everything has gone down, one little piece of poo will come floating back into the bowl. Since it has come back, it is a poo-merang.

noun
(pronounced like boomerang) a bowel movement that inevitably returns with a vengeance after prolonged postponement

verb (intrans)
to experience the return of an urge to defecate, often with increased intensity, after prolonged postponement

When you boomerang (TM) your poop so it looks like you have ultimate colon-sphincter coordination and can suck the turtle head back inside after its poked out.