I have diverticular disease and agree with
@eddie1968 says - I have had 2 bouts of diverticulitis hospitalised both times on drip antibiotics and narrowly avoided an op both times - the first time was also when I got my T2 diagnosis. Also a couple of milder flare ups that I have managed to treat at home with antibiotics from the GP
During an attack it is best to avoid fibre until the infection has gone, but you have to balance this with controlling your blood sugar too - when mine flares up I eat smooth foods like scrambled egg, liquid soups and broths, plain poached chicken. Once I am back to normal I need a high fibre diet to keep me moving and eat loads of veggies, nuts seeds, burgen bread, in fact I have have a low carb healthy fats diet - there is nothing I avoid regarding my diverticular condition although I don't eat a lot of dairy as I'm not keen anyway but also can be inflammatory