I can as MPB recommend Botox. I am 12 weeks out from Botox, sentinel pile removal and fissurectomy. It is minor surgery and I think with Botox alone you won't have any discomfort from the procedure after around seven to ten days. I was back to be comfortable sitting down for extended periods after around a week. I travelled from the UK to Portugal on holiday 2.5 weeks after the surgery and it was perfectly fine. It took a while for the Botox to kick in and I was actually in more pain from spasms after the procedure than before. However, I had had no pain at all for four weeks prior to the procedure but went ahead anyway as I wanted the sentinel pile removed.
I had my follow-up appointment last Friday and the fissure has almost healed. The surgeon hopes I won't have any pain after BMs once the Botox wears off despite the fissure not being completely healed. I'm going for another round of Botox in the unlikely event that I get spasms again once the Botox has worn off.
I can recommend trying Botox if your fissure hasn't healed on its own for this long.