So yeah, all the articles and stuff talk about External . Even pictures and illustrations of Anal fissures focus on things that you can see from the outside.
Why they don't talk about Internal Fissures( which may be deeper in the anus  or in the rectum)?
Cause if i have them, that's probably the ones i have. i don't have external ones

Hay Bob, That is a great question I think a few people here have internal fissure's, just ask, how they are dealing with it.
I'm sure they will gladly help you and give you there advice.
Mine is half in and half out, so I'm told by my Gastro, doctor. Lucky me. the darned fissure couldn't decide.:o 
Just lately, only because I was afraid to do this, very gently for the internal part of my fissure.
I have been applying the Nitro, internally. First I wrap a q-tip with 1/2 a baby wipe, dip into ointment and gently insert 1/4 way only.
I wish I did this earlier, I think it help's more. :)