The practice of blood-letting or bleeding (phlebotomy) was general throughout the medieval period. It was considered a panacea for a variety of ills. In monasteries, monks were treated at set times of the year, which were known as tempora minutionis = time of lessening. They would spend three days in the infirmary, the time the loss of blood - the minutio -was thought to affect the patient. The person in charge of the operation was known as the minutor. During this time, those in the infirmary would not be required to attend matins. In this rather special period outside the monastery's regular routine, it was common for the monks to chatter and gossip in a way that would have been inappropriate elsewhere, although by the 15c much of the inner discipline of the monasteries had dissolved.
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.