@Nancydiane,
It is a very personal choice, but the "informed consent" for the j-pouch is usually lacking. J-Pouch is often referred to as The Gold Standard by gastroenterologists that have healthy colons themselves. I had excellent surgery and follow-up care and still found the post-take-down extremely challenging. Good for that nurse who encouraged you to think about alternatives and make an informed choice!
My history is similar to yours. 40 yrs UC and high grade dysplasia. But my disease had been active for several years before my surgery -- 3 yrs this April. I was 59.
If your surgeon is very experienced in the procedure, J-Pouch is a reasonable option. But the adjustment - physical alone is, in many respects, more challenging than an ostomy in my opinion. You undergo multiple surgeries after which it may take a few years for your body to fully acclimate. During this time the diet changes. When you eat will probably change. The amount of time you will spend in the bathroom on the toilet and the difference in how your gut functions to pass stool without a colon will surprise you. As will the painful "burn" in the beginning that may occasionally return. 12 month later you will wish you invested in a bidet sooner. Your sleep will be interrupted. Maybe for the future. You may feel it necessary to wear a pad to protect against leaking. Most importantly, all pouches have some degree of inflammation, even if only microscopic. Responsible surgeons no longer claim your UC is cured with this surgery. A significant percentage of j-pouchers will experience some form of pouchitis requiting medication. If your surgeon leaves a "cuff" you may experience cuffitis. Given your dysplasia, regular screening pouchoscopies will be recommended. These are the factors weighed against the benefits: an abdomen as you know it - only tiny scars with a laparoscopic surgery - no ostomy opening - no external pouch to wear.
An ostomy if well constructed is one and done. The appliances are an adjustment, but I found my temporary loop ileostomy - typically much harder to manage than an "end" ileostomy (the permanent kind) - actually not too hard to deal with. People have such varied experiences with the loop ileostomy. I found there was more control with the ostomy than with the j-pouch early on. And better sleep. I did not like the idea of it, or the look of it. But I got used to it, and it was not as stressful as I'd imagined. I didn't have it long enough to know if it might have limited activities. But I don't think so. ( The j-pouch certainly did for a few years, and continues to a lesser degree.)
A k- pouch is also something I considered.
Even with the challenges, I don't regret the j-pouch. I more or less have the diet mastered and am feeling very healthy.
Good luck with whatever you chose!