About seven years ago I underwent a total colectomy for torrential diverticular bleeding and, in response to another Medhelp patient's question, I posted my experiences on:-
http://www.medhelp.org/posts/show/523166
You might like to print this off and show it to your surgeon to check whether he/she broadly agrees with what I have written. Of course maybe your surgeon is contemplating carrying out the surgery laparascopically which involves less trauma.
regards
Morecambe