I was dx with diverticulitis about 2 yrs ago... I'm 48 now. I eat pretty much anything I want (I try to be as LC as I can), except that I know nuts are a huge trigger for me. Perhaps everyone is different, but if I stay away from nuts then I do just fine.
I'm glad you're feeling as well as you are. I was SO SICK. It was like the worst childbirth pains I'd ever had. I wrote on my blog at the time "I felt like I was giving birth to something that was very angry with me." And then the meds made me sicker! It was awful.
I'm glad you're feeling better. Perhaps you can think back to what you were eating at the time and do some investigation.