The fact that codeine causes constipation is not, in fact, likely to be a problem when you have a period. In fact, it may even be a benefit! Take codeine today! Lots of it!
Note to others: I haven't bothered to have a "women only" filter on this journal in years, principally because it's a) too complicated to keep track of the gender identities of some of my friends, b) some male-identified individuals may still be able to sympathise with icky girlstuff and c) the remaining male-identified individuals should at least be aware of how icky the monthly female experience is for a lot of us. Also, it's not like it's particularly private that I'm having a period! I only post friends-only when I feel that something is genuinely private, and this aspect of my health really isn't one of them.