noun, plural fis·tu·las, fis·tu·lae [fis-choo-lee] /ˈfɪs tʃʊˌli/.
Origin of fistula
Examples from the Web for fistulae
Dioscorides says that fistulae may be dilated with sponge tents.
In other cases this extreme result is not caused and fistulae are formed from which the ichor constantly flows.
The ear probe seems to have been much used for probing wounds and fistulae when a very slender instrument was required.