I don't know but from my personal experience, as I haven't been on here much to have observed long term jpouch history across the patient population.
for me the first major SBO (small bowel obstruction) that led to surgery was arguably due to adhesions about 18 years out from my initial surgery. I was shocked at this but was informed that acutally about 20 years or so is the typical time frame for abdominal surgery adhesions to take hold. I was told that the more common adhesion problems were women who had C-sections 20 years later. fascinating.
eventually I developed two strictures in my jpouch and ever since then it has been arguably those that have caused my obstructions. logical to my mind as quarterly dilations of those strictures as well as med changes seem to have kept me out of the ER and other obstructive symptoms. but if you don't have strictures then you don't have strictures.
personally I avoid fiber like the plague, but I know some people including jpouchers seem to tolerate fiber. rabbit food to me, makes me think of shitting like a rabbit so while they are undoubtedly cute animals I'm not sure how much I want to be like them. the world as a whole loves to tell people to eat fibrous foods but my experience is completely opposite, apart from jpouch complications, structuring - pouchitis etc, I wonder how poorly my health is impacted by my dietary abstention from fiber. I think its not negatively impacted and while morbidly I do expect to die before the actuarial tables might suggest, I don't think it will be lack of fiber that will be the proximate cause. I run half marathons regularly for the CCFA, and I also push weights around the gym for giggles. I have noticed as I get older that the weight starts sticking around more, so abstentions from fatty food choices ie desserts, snacks etc become more important. that's how I battle the weight gain.
good luck to you figuring out your food choices, maybe more modest adjustments to see what works for you? I have often seen well meaning nutritionists who have zero experience with IBD, let alone jpouches virtually kill people with their directions, which might well apply to the average person, but remember we have jpouches here, so we are all above average. ;-)