That may be a tough call for your son depending on his age. i think depending on the stricture some people have success self dilating but if the stricture is very fribotic or a result of cuffitis it may not work. I’m in the same position and I’m going in for pouch advancement surgery
I have had multiple dilations under anesthesia and my stricture will not stay open and each time they dilate they just create more scar tissue in my case. Some surgeons are really against self dilation and others are ok with it. Purchasing hegar Dilatiors and using small ones initially may help but i would really suggest discussing this approach w your son’s surgeon or GI as they do worry about the potential to perforate the pouch and may possibly suggest excising the stricture and advancing the pouch as they have done in my case
Good luck. I know how debilitating this is.