Hey db56! I'm so sorry you are still suffering! I think Dawn is right that an overly conservative cut might prevent the fissure from healing. A few people here a had to get a second LIS because the first one wasn't sufficient. That really sucks, but I think that too conservative is better than too much! Also, a few boardies used ointments (like nitro or Diltiazem) to finish the job after their surgery - especially if they still had spasms. So that might work for you - maybe you could ask your doc about it.
A few boardies took valium, like Dawn, and it worked quite well to minimize the spasms. Another boardie, Elphie, took oxazepam, which is like valium, but not as addictive.
I HATE it when doctors make blanket statements like "there's no such thing as too much fiber"!!
They should know that there isn't one amount of anything that is good for every person. We are all built differently, and there most certainly is such a thing as too much fiber for someone with IBS or celliac disease, gluten intolerance, or even relatively minor intolerances and allergies etc. Body weight and metabolism matter too. Sheesh! IMO, you should work out a combination of soluble and isoluble fiber that works for you. As long as you are getting enough fiber for you, and most importantly, drinking enough water, you will be quite fine as far as BMs go.
Unfortunately, it looks like you might need some medical interventions to deal with those spasms. I really think you should talk to your doc about ointments and meds (like valium).
I really hope you find relief soon!