A Square Anus or Rectangular Poos?

Producer Nick wants to know if we had a square anus would it come out in a square shape? Probably not. We do still have the problem of why the wombat produces rectangular poos or sorry cubical poos. There is a bit of a theory coming down the line on this and it seems to be related to extra musculature inside the tube so you've got the tube of the large intestine that can turn into a cube. The trouble with having a square anus is that at the end of each bowel motion the lips would come together with an awfully loud bang.