Hey MONI07
I've heard of Dr's missing internal deep fissures before in here, especially if they are hidden underneath a fold and if your not dealing with a CRS. (buzzword "second opinion")
Here's the thread link here on "hidden fish"
http://anal-fissure.org/t6910-anyone-have-fissure-far-insideHey listen, you may be an ideal candidate for self exam shower finger probe. You say the Dr. did it to you and you did not mention too much discomfort from this.
This may help you in the long run to better understand how your progressing in your healing phase. For years the shower finger probe has helped me to learn a lot about my fissure and even today though I've been healed for a long time now I still use that technique to gauge when the canal is getting weaker.
That gives me a head-start to combat any new fish trying to swim upstream if you know what I mean (saved me from re-tears also). It doesn't appear that you suffer from being to tight down there where this is not possible. Give it a try.
I'll completely understand though if you will not feel comfortable doing this, and if so no problemo.
HTH GL