I had an LIS performed in May of last year. I would say it was 95% successful in that total days spent in agony are now a few days every few months, as opposed to almost of every day of every week before the surgery. However, I re-visited my CRS to see why I was still having occasional pain and after a quick examination he said that I now have a superficial fistula and need yet another procedure to make that lingering pain go away.

Could poor-healing of last year's surgery be a culprit of this fistula? I'm scheduled for a fistulotomy in 2 weeks and am eager to get this remaining pain out of my life, hopefully forever. But am nervous as I've read that recovery from this is more painful than LIS, and somewhat concerned about another procedure not healing properly and causing further complications. Is this even a valid concern?

A fistula is definitely one of the complications possible when you have LIS.

Fistulotomy has its own possible complications, which you can google, or ask your surgeon about (that way you'd know how often his patients have them).

Hopefully though, you'll be like most, and have an uneventful recovery.