
It was revealed earlier this week that King Richard suffered from roundworm parasites in his gut. For more information see:- http://www.bbc.co.uk/news/science-environment-23878424
Given the insanitary conditions of the time and poor hygiene, parasites like roundworm must have been endemic. Archaeological evidence of astringents to clear the gut of such parasites have been found at Soutra hospital near Edinburgh, a medieval hospital that straddled the main highway between England and Scotland. Excavations there yielded the secrets of an extensive pharmacopoeia:- http://www.independent.co.uk/news/prozac-opium-and-myrrh-the-ancient-arts-of-anaesthesia-are-unlocked-1238659.html

See also:-
http://militaryhuntingandfishing.com/sites/default/files/Medicinal-Plants-in-Folk-Tradition-2004-Allen-Hatfield.pdf
for information about herbal treatments.
I stress that this information comes with a health warning and you shouldn’t try this at home!
