A common occurrence in those suffering from digestive issues; especially diarrhoea. This happens when you go to the toilet, feel as though you've finished and start to wipe only to have to sit back down and start the process over again. If this is repeated more than once, you end up with a layered effect (poop/paper/poop/paper/poop/paper etc.), much like the layering of a lasagne.
When I got in from the pub last night, I had myself a shit lasagne.