Evan, you may wish to refer back to my response to your prior post. There really is not much difference between a J pouch, end ileostomy and BCIR (or similar K pouch) as far as fluid absorption is concerned. With each of those procedures, it is essential to drink additional fluids to compensate for fluids otherwise absorbed by the colon. My personal choice would be to opt for the J pouch, which has a high success rate. If you select a different option and your bottom is sewn closed, you will never be able to get a J pouch later. If the J pouch does not produce satisfactory results, you can go for an ileostomy, K pouch or BCIR. There will still be sufficient small intestine for any of those options.
I have had a BCIR for 4 years with excellent results. With this procedure, the surgeon creates an internal pouch and valve using a short section of your intestine. The pouch is emptied at your convenience 4-5 times a day using a small silicone catheter. There is no external bag required. This procedure is now being performed in London by Dr. Ed Westcott. You can view a lot of information plus a video presentation at www.bcir.com.
Bill