Has anyone experienced delayed LIS healing before?

Had my LIS a month ago and everything went extremely well, painless... Until I got diarrhea two weeks ago (3 weeks after LIS). Stomach flu and diarrhea lasted for a couple of days, and since then the pain during and after defecation comes back again.

Is this normal?

I believe this is normal. It can take a long time to actually be healed down there. You may have had an absence of pain but that doesn't mean you were quite healed yet. The diarrhea may have flared things up but having had the LIS, you should heal up quickly again.

I sympathize with you stephencurious. I unfortunately experienced diarrhea after my LIS too. I was fine on day 3 when I had my first BM and was regular that day, but then days 4-6 it set in (from the antibiotics, which always seem to do this to me no matter what preventative measures I take). I definitely ramped up my pain, which was surprisingly not bad with the first 2 BMs, up to an "OH GOD GET IN THE SITZ BATH NOW" level upon finishing a round of the runs...probably the worst pain I have felt. I was worried too about delayed healing or possible infection from this, as it aggravated the fissure and seems to rough up my incision, but luckily once I finished the antibiotics it resolved itself and within a couple days the pain greatly diminished. So I guess I don't have a for-sure answer, but it seems like once it has been gone for a few days, your healing probably will resume. I hope you are already starting to feel better!