How do you study the hygiene of people living in the past. By studying their feces of course.

Researchers from the University of Cambridge have studied the latrines at Saranda Kolones castle in Cyprus, which was a Crusader stronghold built in 1191 A.D. during the Third Crusade.

Tests on latrine samples in the Saranda Kolones castle, a crusader fortress which was built after King Richard I of England captured Cyprus during the Third Crusade in 1191 AD, showed two species of parasite eggs, the roundworm and the whipworm, prevalent in the soil of what was once a cesspit.
Both types of parasites can live in the human gut, and their eggs are released through bowel movement.
The parasites are transmitted orally and evidence of their presence reflects the poor hygiene conditions that prevailed in medieval castles, according to researchers Evilena Anastasiou and Piers D. Mitchell.

I wonder what future archaeologists will find in our poo?