After I found out I had fissures the dr prescribed nitroglycerin ointment and fiber. My fissure went away after about 3 days. I continued with the nitroglycerin for about a month and then quit. The fissure returned.
I had noticed the new fiber I was taking didn't do as good of a job so I went back to the fiber I had been taking which is the Walmart Equate version of "Metamucil MultiHealth Fiber Active". After a few days, the fissure went away again and has stayed away for several months.
So some fiber supplements seem to work better than others. And the Metamucial Multihealth Fiber Active pills, or equivalent, seem to work good enough for me to completely eliminate the fissure.
As a side note, I will mention that before taking fiber I was completely regular. I eat a high fiber diet and a small amount of meats. However, it seems that wasn't enough without the fiber supplement.
Please try something like this before thinking about surgery! Hope it works for you.