See this thread:
http://j-pouch.org/eve/forums/...127007026#3127007026It's important to get one every year (according to Dr. Bo Shen and Dr. O, his disciple and my GI) due to the threat of rectal cancer in the retained cuff, especially for those who had a dyplasia diagnosis before colectomy. Note that this data is just getting realized because they have only been doing J pouches in mass production since around 1990 or so and we now see people living 20 plus years with the pouch so this date just is coming available.
Others, possibly less concerned with or oblivious to the CC findings, say every 2 years, and others say no scope at all unless you have some issues. This sort of plays a game of roll the dice with your rectal cuff and it is up to you if you want to participate in that dice roll.
Dr. O told me the CC data shows enough to warrant annual scoping to get biopsies of that rectal cuff. That is where it will start if you end up with cancer in the pouch. But, he stresses that cancer of the ileal pouch is rare.