Feeling extremely down right now. I have been doing so great for 3 weeks..no pain or anything, smooth BM's then today after a painless BM I got a spasm. I have been tight all day and during my last BM I could not pass anything because I was in such a tight spasm. Then about an hour later I felt the need to go again and could only get a tiny bit out. I'm not constipated as my first two BM' were perfect so why would I get a spasm after painless BMs? I'm so afraid this is going to aggravate my AF's or worse, constipate me. What do I do? I sat in a sitz bath already and massaged in nifedipine. It relaxed the muscle but it tightens as soon as a I feel an urge again. I'm so fed up and done with this I just cry and ask why I have to go through this.. I eat healthy, take Miralax every night, keep up on the nifedipine. I don't know what to do anymore!

Oh gosh ! ..  Ok, don't panic.  Spasms don't aggravate fissures that are healed.  It is not too late.  Tomorrow morning your BM would be fine, because you haven't stopped taking your Miralax yet.  Don't get stressed. 
Sitz bathing and applying nifedipine are the two best things that you did. It will help you tremendously to have a smooth BM next time.  So please please please relax.  Don't think about it.  Let the cream work on your sphincter muscles.  Stress causes the muscles to contract, so please, while having your BM tomorrow morning, try to exhale more.  You will be fine.  I will be praying for you.

Yes, I agree.  The great news is you aren't having pain with your BMs. Keep reminding yourself of that. the sphincter muscle is likely responding with muscle memory for the fissure and is just responding out of habit. The worst thing you can do is get really stressed and panicky, which will make the muscle even tighter. Just keep doing all the things you are doing, and focus on your breathing and on relaxing during your BMs. Breathe deeply into your lower abdomen. Fill it like a balloon. This will help to relax the pelvic floor muscles.  Just keep reminding yourself the BM itself was painless and hopefully your sphincter muscles will catch up and unlearn their spasming response. 
Wishing you a more comfortable day tomorrow.

How are you feeling today?  Hope you are trying to stay relaxed.  I know it is the most difficult part, but you have to be strong and let go of that fear. 
You can stop spasms by gently touching the end of your tailbone (it is a chinese medicine trick to stop spasms)  Well, they even say to press it gently but I don't want to recommend that.
So try this trick and also remember to exhale (more like sighing) while you go.  Hope it helps.
Take loads of care.

Hi Kreaybutt, 
I'm so so sorry you're in pain. Just know that I'm sending you a BIG BIG hug. 
I think the worst part of the process for me is the ups and downs. One day we think everything is fine, the next day our bum's falling apart again. But it's progressive. I really believe that our bodies have an incredible ability to heal themselves. We just do the best we can by using our cream and our baths. It sounds like you're on the right track and taking care of yourself. 
Hang in there and BIG HUGS!

Thank you all for you're help and support. Today's BMs were better, though a little too big and bulky so I think I'm getting too much fiber. I absolutely hate this good day bad day thing. I just want to be back to everyday being good! I wish you all healing and happy days! Oh and touching the tip of my tail bone actually really helped!
Mabs-I wrote you back in a PM!

MMMMmmmmHHHmmmmm... Everytime I see Pizza I mourn the day my bum gave way! Of all the things I take for granted in life, pooping was for sure the biggest one!
We'll get there... We just gotta stay positive and keep chugging.

So turns out that it's going into spasm before passing gas too. Which is even more uncomfortable. I'm sitting in a hot bath and its still not going away :(

Oh Kreaybutt I'm sending happy and hopeful thoughts your way.

I was having the same problem today... Couldnt get nothing out, lits of tightness. I took half a 250 mg magnesium, drank a little bit more miralax, like a quarter dose because i was backed up. Ok i took the magnesium three hours ago and the miralax like an hour ago. All day, backed up, couldnt go until i just went a couple minutes ago and everything came out it but i was a little flustered but so relieved right now. I just kept thinking do not push do not push. I have been blood free minimal pain, my sentinel pile was shrinking all week... I felt i was healing and today i was not going to let anything rip my butt open! I think magnesium helps with the tightness in the pelvic region for me and i am going to continue with this supplement here and there. I think my constipation and straing  starts up in my intestines... Not at the rectal area. I wish i would have known about the magnesium and miralax before i tore. I could have prevented this.