First of all I am sorry you are going through this. In the couple years after I got my pouch, I had around 4 blockages or obstructions. If that's what you are going through, I know it sucks, but even if it's not a blockage it doesn't make it suck any less.However no BMs in 3 days makes me think you do have a blockage/partial blockage. My experience with them was that they got worse over time and I experienced a knotted up sensation and then increasing pain. I needed a NG tube for one of them, but 3 others alleviated when I began vomiting. The violent wretches and spasms of my abdomen during vomiting seemed to have dislodged the plugged up food. One time I was all the way to the ER and they were just about to NG tube me when I started vomiting and the blockage freed and I moved my bowels.
As you may know, I am also strictured at the Pouch inlet, although I have a 30 year old pouch and that stricture built up over 29 years, probably from backsplash stool and pooling of stool above the inlet, which caused inflammation over time. My stricture closed up last year to the point where my doctor couldn't easily get a scope through summer of 2021. After that I had 3 dilations which created an 18 mm clearance in the inlet.
During the time I was strictured badly, I never had a blockage or obstruction. Therefore I am not suspecting the issue is your "slight stricture."
If you continue to have no BMs, or start having pain, get your ass to the ER and let them figure it out. Any sign of worsening, or pain, get to the ER ASAP.
STOP taking anything that slows down your bowels. No booze, marijuana, pain meds, or anything else that is remotely constipating. Also including the antibiotics. I have a friend who was popping oxycodone like candy after 3 level cervical disc fusion surgery and he ended up in the ER with "impacted stool", in others words severe constipation. They had to perform a fecal disimpaction on him.