Per rectum: a history of enemata.

Enemas and clysters have been administered since before recorded history, using instruments ranging from cow horns and hollowed out bamboo shoots to metal syringes to inject laxatives, herbs, opium, turpentine, tobacco, oxygen and noxious chemicals. The potentially lethal dangers are today well recognised. The rectal route, now less often used for laxative enemas is still proving useful for other medications, increasingly in suppository form.