I've had 3 bouts of diverticulitis. No doctors really gave me any info on diets to follow.
I had 2 opinions on surgery. One said take out sigmoid colon. The other said not yet.
I since 3rd bout spoke to a new primary about diet, bought a book on diverticulosis diet, and have been communicating with a very nice PA in the colonoscopy practice. I had been dieting and constipated Which I think contributed to the attacks.

I still don't eat as much high fiber as I did before the last attack. I am still afraid to eat popcorn, because I had a big bowl of popcorn before my last attack. The PA told me Miralax every other day to keep stools soft. On the off days I have 2 prunes and/or prune juice. I don't mind them at all . I have Benefiber in my morning coffee every day. I had tried Metamucil-it's gritty and nasty in my opinion! I have recently added a granola bar as a night time snack. I would say my diet is medium fiber. I eat cashews, lettuce, canned peaches, seedless watermelon. Very little beef-and I was raised on beef! Mostly chicken and turkey. Cooked green beans. rice, mashed potatoes. I'm a finatic on having a BM daily! If I start to feel a little uncomfortable on left side, I go liquids and soft foods for a day or two.

Look on Amazon or at your library for books on diet, or just Google "Diet for Diverticulitis.

GOOD LUCK!