Human poo is only preserved when the conditions are right and it can dry out and harden instead of breaking down. When this happens the remains are called palaeofaeces.

Since most people used cess pits for toilets in medieval times the preservation of poo is rare.

Palaeofaeces can look a bit like fossils due to a coating of sugars, from inside the poo, forming on the surface of the poo.

Palaeofaeces can be examined to find out what food people were eating and how healthy they were.