I went through this at a young age, 21, in 1986. No one gets diverticulitis or diverticulosis when they are in their twenties!
Anyway, since I was so young the quacks at the hospital were sure it was kidney stones and they sent me home to pee in a strainer. I came back two days later when the pain was still there, and they admitted me. Two days after that, I spiked a fever and my gut swelled up like a big balloon, real hard like a balloon that is about to bust. I went in for emergency exploratory surgery.
I woke up in intensive care, split open down the middle from the bottom of my sternum to just above you-know-where. There were four big stiches holding me together, i wasn't zipped up permanently, because in six weeks they were going to have to operate again. You see, I woke up with a temporary colostomy. They had to make sure the perforated part of my colon (which caused peritonitis) could heal, then they put me back together again. I would hate to go through that hell again.
At the point where my stoma was, years later I developed a hernia. I lived with it, and off and on I would have more diverticulitis attacks. I would go to the Dr., tell him what was happening and get some strong antibiotics and it would go away. Finally in may of 99 I had a REALLY bad attack that put me back in the hospital. I had the hernia repaired, and I have not had any problems since then. I was told if I ever DID have anymore problems, I would most like lose the rest of my colon and have a permanent colostomy. When I had my first colostomy I told myself that if it ever happened to me permanently I would rather die. Of course I was young back then, and my attitude has changed drastically.
Be careful. I wouldn't have the surgery unless it was absolutely a medical necessity. Sounds like yours is not at this time. Keep getting check ups though because people with this problem develop polyps and you know what that leads to.
I was told to avoid popcorn, nuts, and especially sesame seeds. Stick to a high fiber, low residue diet and I would be fine. I've strayed from that considerably over the years (except for the fiber part) and I have been fine in that department, knock on wood. My most pressing problem at the moment is heart disease.
Good luck to you.