I was diagnosed last year with diverticula disease, after suffering from chronic diarrhoea, and stomach pain for over a year. I was surprised by the diagnosis as I eat a plant based diet. To be fair, I have also eaten crap!
Anyway, for the past few months I've increased intake fermented foods ( I make my own kimchi). I also drink diluted apple cider vinegar about twice a day. I actually like the taste so no hardship.
Since doing this my gut has significantly improved. I have also stopped taking nsaids, as I noticed gut pain after ingesting. It's a pity I can't take them (even with omeprazol) as they do help, but I've taken them for years and I don't think they're doing me any favours. It's not a good idea to take them with diverticula disease anyway.
Just thought I'd share improvement in case anyone else is suffering with gut issues.