Hi reidgirl,
Everything I know about my fissure I have learned from this site, so I really don't know what to call what I've experienced. I looked up proctalgic fugax spasms
(http://www.embarrassingproblems.com/problem/anal-pain and
http://en.wikipedia.org/wiki/Proctalgia_fugax), and their description of them occurring for only 20 minutes and mainly in the night didn't match for me.
I found some other older posts here, just doing a quick search (I hope the link works for you):
http://anal-fissure.org/t2133-levator-ani-syndrome-or-proctalgia-fugax?highlight=fugaxhttp://anal-fissure.org/t234-painful-bm-past-spasm-comes-on-2-3-hours-post-bm-why?highlight=spasmhttp://anal-fissure.org/t1364-what-do-sphincter-spasm-feel-like?highlight=spasmI can only tell you that I have experienced three different sensations which I think are muscle related
1) there's a constant tight feeling, which to me felt like the muscles wanted to push themselves out of my body - but this was mainly uncomfortable, not painful
2) after a BM, it felt like rather regular sphincter contractions that would last about one hour, that heat would help. This was painful, and all I could do was sit on the heating pad, close my eyes, and pray it would go away. This stage lasted about 3-4 weeks for me.
3) what I've called zingers is like a single but more severe muscle cramp that can happen any time of the day. It comes without warning and feels like a muscle squeeze and a knife jab at once. It often makes me cry out loud.
I think some others can give some thoughts on this.
So sorry you are in pain - I hope you can get some relief.
Do you have any of the ointments, like diltiazem?