May I refer you to a previous posting of mine:-
http://www.medhelp.org/posts/show/523166
From this you can read a "blow by blow" account of the total colectomy operation which is probably similar to the operation that may be envisaged for your condition.
Then I would check with your surgeon whether my description is similar to what you would undergo.
Then I would suggest that you make up your mind as to whether you have the appetite to undergo this big operation weighing up the benefits of the cure, and the risks/odds of complications that you must ask your surgeon to describe to you honestly.
Lastly what are the risks of not having surgery. Could the diverticula suddenly start to bleed (torrentially) as mine did? This can be life threatening if you are not close to a hospital.
Take a written list of questions with you to the consultation so that you ventilate all your concerns especially those that may be relevant to your previous surgeries.
Good luck
Morecambe