Besides having my current surgery, I also had a hemoroid/fissure surgery 5 years ago. You will have swelling down in that area from the surgery. I know that I wasn't able to pass a gas bubble either from this recent surgery or the one before. And when I did, well I never realized that bad a passing bubble can be. Once you are able to go, it will be painful, but will get better day by day. I found also after you go, take a nice hot/warm sitz bath for 15 to 20 minutes after each bowel movement. That helps me a lot
, with the pain and the spasms after passing a bm.
I hope the Milk of Magnesia works for you, but I understand why you may go to the emergency room. Because I did the same thing the other day, but I called the Same day Surgery part of the hospital first and they told me they couldn't do anything for me with just having the surgery and to call my doctor first. Because if the Milk of Magnesia wouldn't have worked I also was headed for the Emergency Room. Please let me know how you make out and I hope that all goes well.
My thoughts and prayers are with you.