when you do you enema you do it in 2 steps right?
one plain water - 15 to 20 minutes in between to get rid of yeast in the last bm - another one : retention enema, with the nystatin this one remains inside and rehydrate the colon. like dvroge says: if you use nystatin - it will kill the culprit - if you use butyrate - it will help restore the natural flora.
if you do not wait in between - the yeast will be irritating and the retention 2nd step wont work