Why isn't cauterization of anal fissures a normal procedure? It seems to me that if you can force the lining to heal with a tough scar, and kill the nerves in that area off at the same time, you've fixed the problem - it shouldn't rip open again and the pain should be gone. What am I missing?

I'm not sure either! But just speculation - this is probably an area where you'd want avoid lots of scar tissue and possible stenosis...maybe natural healing is just cleaner and causes less problems in the end.

Also, I think LIS is so successful partly because some people just have a too tight sphincter. This may be genetics, or maybe they had trauma to the area, like a fissure, and things just never go back to normal, and they'd be predisposed to future fissures, hems, etc. So LIS (and certain tropical creams) treat both the symptom (the fissure) and the instigator - whereas cauterization would only treat the fissure.

Dunno, just a guess!