If you were to have your J pouch removed and your bottom sewn shut, you would not be able to have another J pouch at a later date. A manometry test would tell if your anal sphincter muscles were strong enough to support having a J pouch. I opted to continue with a J pouch for 30 years even though I experienced 12 BM’s a day and some leakage. You could always go to an end ileo or a continent ileostomy if the J pouch did not produce acceptable results. The two continent options that do not require having an external bag are the K pouch and the BCIR. There is plenty of information about these options on the internet.