I'm sure it can be reversed as many other have talked about. The only issue I see with it is the amount of time you spend with the pouch inside not functioning. There haven't been many studies in areas like this, with a potentially useful organ being unused for long periods of time. I'm sure we all know the term "if you don't use it, you lose it". Well, this actually can apply to several things, for instance if you dont use your muscles, it will cause atrophy and they will shrink in mass. I would assume that with an unused organ just sitting inside taking up nutrients, for every few years that go by, the chance of having that organ re-integrated into the body and completely functional with no problems has to decrease. You also have to take into account the individual's age. The chances are probably also much better for something like this in a younger person than an older one. Nonetheless, in theory the JPouch could be re-hooked up again and function efficiently after the bag.