Colorectal surgeon said i have obvious posterior anal fissure & gave cream to heal. what does obvious posterior mean? is it really bad? healing well.

No most common site: Don't worry it is not bad , most common site located at 6 o clock position in lithotomy position , follow your doctor's advice

Nothing special: This is a typical location and sounds like a typical fissure. It should improve with the medication.

Obvious means seen: Obvious just means that the fissure was easily detected on his exam. Not a bad thing, just proof of a solid diagnosis. Continue your treatment.