Diverticulitis is a tricky little issue to manage because to me it is hard to tell what is setting it off. I was hospitalized after third bout and an acute flare up is no fun. I found the dietary aspects difficult to determine as well. I would say with flare up go liquid for a few days, if that helps go low fiber 7-10 days, then slowly every 3 days add a higher fiber food. Raw food like lettuce, carrots I would add last. I also stay away from cabbage, broccoli and other cruciferous type veggies. That advice came from my colorectal surgeon. So far so good. A dietician would be good as every one individual is different. Good luck!