The main reasons I was given:
1) The small intestine is not as elastic as your colon. You risk rupturing your pouch.
2) The J-pouch is attached to what is left of your rectum, you could tear it loose or cause leakage at that site.
3) Unspecified "serious" injury
Even the thought that I might need surgery down there again is enough to keep me from even trying again. You know?
I hear yeah.