Bobish. It's like déjà vu. I was diagnosed with dysplasia and given same option. I chose to go for the j pouch as I did not want to go for the constant screenings or risk any further developments. I had a two step surgery as I was also for the most part healthy.
Step 1- removal of colon and development of j pouch and temp ileostomy. The recovery from this one I found most painful. First 5 days post op was hell but manageable. Try to walk as much as possible. The bag was a bit of a shock and it took me about three times changing in it while at home with a nurse to get the hang of it. Once I did it was pretty easy. Emptying the pouch is easy annals manageable. If there is one thing I liked about the bag was the ability to empty it at my discretion. There is some initial noise in the first days post op while the stoma comes alive. Don't panic. Goes away or is less noticeable after a couple of weeks.
Step 2- Ileostomy reversal and j pouch hookup. I am currently 18 days post op. Pain is no where near the 1st op although there was some. The biggest adjustment for me was and still is adapting to the new plumbing. Man does the system was up violently once you start eating solids again. This is the part that has caused me most anxiety. There is a lot of gas in the beginning rumbling through the system. Frequent bowel movements that were for the first couple of days watery. You need to manage this with spray bottle flushes and barrier cream as it can be sore. This has got better with more time.
That said, I am still adjusting. My bowel movements now vary. Sometimes watery and some more formed (not like before removal of colon). The thing that still irks me today is the sudden onset feeling that can come and sometimes an hour after I already had one. And because it's hard to tell wether it's gas or stool, it has made me panicky. However, based on what more experienced j pouchers will say, that it takes 3-6 months for your pouch to adapt fully where you get the feeling but it is easier to manage.
Therefore, there is adjustment from a bodily function but what i do like is my body without the bag. And worse case scenario, if things do not work out, I know I can always go back to the bag. That is worse case. I am thinking optimistically as I am longing for the day where I can feel confident in being out and about. I am just starting to do that now. My mornings to mid afternoon seem to be best. After that my bowel movements times seem to be era tic. I am on average going 8 times a day (currently) and trying to feel better more confident about myself. It's slowly coming. But this is my biggest hurdle.
Whatever decision you make, I hope you can use this info and get all the info you can on what to expect post takedown surgery as this is something I wish o had so I would've know what to expect myself. No one told me that my system would be waking up once again and be erratic. I had to figure this on my own.
Good luck with your procedure. I know it will be fine. Just be prepared mentally and you will get through it. So many already have. And don't worry so much as I did about the possible complications. My doctors didn't seem to be to worried. That were very positive.
If you need anything, don't hesitate to reach out.
Good luck.