what was the Roman Catholic/Orthodox canon law?

Greetings: I am trying to find written resources on Roman Catholic/Orthodox Canon Law concerning menstruation in medieval times. It appears that women were restricted from attending worship during such periods, apparently based upon the biblical book of Leviticus. No one seems able to help me with this, so I am turning to you! And: I had another question, related, but I thought perhaps "outside your ball park." Anyway, here goes! Nocturnal emissions of semen render one ritually impure for a short period, according to Leviticus (a reflex, I think, of the "pagan" ideas of incubus/succubus). In medieval canon law, the question (as I understand it) was: Can a priest celebrate the mass after such an experience the previous night? Answer: Only it it were inadvertent; but if he went to bed thinking of lusty damsels and thus precipitated the event, no! Can anyone cite text on this? Many thanks. Lloyd Bailey lloyd@duke.edu Professor of Hebrew Bible Duke University Durham, North Carolina U.S.A.  more