My brother suffers from diverticulitis and has been helped by drinking homemade kefir morning and night on empty stomach, and by eliminating all grains and flours from his diet. He has also eliminated sugars and the only sweet he eats is fruit. The kefir helps because it is full of diverse anti inflammatory good bacteria, probiotics. I know this is (particularly) helpful because I make the kefir, and due to my own illness was unable to make for a week. My brother, unable to drink the kefir, ended up in hospital for two weeks. Yes I felt absolutely terrible, but on the plus side we were all able to see how beneficial it was for him. I would aim for kefir, but other probiotic foods are organic (unpasteurised) miso paste, tempeh, sauerkraut, kombucha, natto.