I thought I'd offer my positive experience, especially since I noticed most topics are about LIS, and people were very helpful and supportive when I was freaking out about getting diagnosed.
I developed a very deep fissure in early September. At first it was just blood, no pain. It grew progressively worse for about a week--first more blood (alarming amounts) and then pain, and lots of it.
I had to jump through a few hoops, and saw 4 doctors in 3 days, but I ended up with a general surgeon that third day who scheduled me for surgery the next day. (Interestingly, I did see a colon/rectal surgeon, who only saw blood and told me to go home as it would fix itself eventually). The general surgeon diagnosed me with an anal fissure and probable internal hemorrhoids. We decided not to do LIS, and to just remove the fissure/hemorrhoids if needed.
Surgery went smoothly and I did the fissure and internal hemorrhoids removed. Other than the anticipated nausea when first recovering (not a surprise, happened before), everything felt numb and great. That lasted about 2 hours from waking up, then came the pain. Intense, can't be prepared for pain. About 24 hours of curl up on the couch, drug yourself senseless, try and not cry into a pillow pain. The only thing that helped was an ice pack (and the vicodin, but barely). I ate super light and cautiously for about a week, week and a half. The idea of bowel movements was more scary than actually having them. Light bleeding for a week or so, then nothing. I was sitting (on a pillow) after about 4 days, driving after a week. All discomfort stopped after 11 or 12 days. 4 weeks out, I'm now totally fine, no pain, no blood. Only side effect was some skin tags from the swelling.
I know there are lots of factors for waiting with surgery, but I can't stress enough how glad I am I did it, and so quickly. I was "lucky" enough to be not working (although I actually accepted a job the same day I had surgery, but that's another story) and to have doctors who considered my case urgent enough. It's painful, but only temporarily, and so worth it.