Coil one down 

To have a shit, especially if caught short and no conventional toilet is available necesitating that the said shit is delivered from a low height, such as in the woods.

Extendible however to any situation where a person has removed themself in order to defecate.

Where has your wife gone?

Oh, she has just gone to coil one down, she will back shortly.

Coil one down by JLMW September 4, 2011