Hi Lisa,
I am so sorry for everything that you have been going through...it sounds like a really a rough ride for you.
Did they tell you why you had toxic mega colon? UC or Crohns or something else? The fact that they left you with some colon is (maybe) a positive sign that there was no crohns disease which is usually (but not always) a deal breaker for a k pouch.
The k pouch is one of 2 variations on a continent pouch (k pouch and BCIR)...and the J pouch is a pouch that uses the natural exit (means that you have a functionning anal sphincter) and that there is no reason why you cannot have a normal exit (anal/vaginal fistulas are also possible deal breakers due to the placement of the pouch). That is usually the go-to pouch when all things are going well.
When the natual exit is compromised (a weak sphincter, fistulas or a failed j pouch...) they can offer you a k pouch or a BCIR. Both are consturcted similarly and are based on a pouch made out of a section of your small intestine (just like a j pouch) but they use about 8 inches more to create a one-way continent valve with a small stoma that sits low on the right side of your abdomen. When your pouch fills up (you get a full feeling just like when you need to pee) you empty by inserting a catheter (you need to lube while yo are at it) or tube into the stoma. The "stuff" and gas pours out of your pouch into the toilet or a container. When you are done emptying out your pouch you rince out the tube and put it away (I reuse tubes for years) in a bag or case and then wipe off the stoma and cover it with a protection ( I use a folded up kleenex but some people use bandaids, gauze or patches).
I also carry a 60cc syringe that I use to irrigate my pouch when the stuff is too thick to pour out easily.
Most of the time the k pouch is a no brainer for me...I don't even think about it...I eat normally (normally for me meaning I still limit my fibers like corn, peas, cabbage and other gas forming legumes plus I don't eat a whole lot of carbs for both weight and fluidity reasons and I avoid too many milk products. Most colonless people have problems with lactose)...it is natural for me and poses few problems.
The problems that you can have are usually due to a weakness in the valve or a complication with the pouch. The downside with all pouches is something called pouchitis that is a sort of pouch infection that can usually be treated by a run of antibiotics (not always easy to treat).
I am sure that the others will add useful information for you but do not hesitate to ask any and all questions that you have.
I ho;pe that this helps you a little with your decision process
Sharon
ps. Most pouchers whether they be k pouchers, BCIRs or j pouchers are out living their lives and don't hang around these sites...those that do are either pre-pouch like you or living through the process of having one done.

Thank you so much for your helpful response. I am in touch with Dr. Schiller in California who does the BCIR procedure and will be sending him the required medical records soon and am hopeful that we might be able to do something. Can you possibly offer any comments regrading the information regarding the differences, pros and cons, between the K-Pouch and the BCIR? Thanks again.