I had 3 endoscopic balloon dilations in late 2021 and early 2022, but my stricture is at the J Pouch inlet, not the outlet. So it was not really impacting on my Pouch function but was concerningly causing stool to backsplash and possibly creating inflammation upstream in the neoterminal ileum. The 3 dilations were all done under conscious sedation at my request and increased the width of my stricture from 7 mm to 11, 15 and then 18 mm. I had a pouchoscopy last month and remain dilated at this time.
You might need multiple dilations. If they try to dilate too much and too aggressively the bowel can be perforated, so they generally go slow and gentle lest you end up with the dreaded bowel perforation and, potentially, sepsis. This is the main concerning complication. I was dilated by an Advanced Endoscopist at Yale, who had done many such procedures. He explained to me in great detail in a Zoom conference his dilation strategy. I would suggest you have an in depth discussion with the doctor who will dilate you on these same issues- namely what is your current width of the stricture and what the initial dilation goal will be in millimeters. They should go a few mm at a time.
Good luck.