Do they do a colonoscopy to diagnose it for certain. My diagnosis was done simply by the symptoms and with all three attacks I'd eaten strawberries.
My Mother had a colonoscopy, and lower GI studies, and abd ultrasounds to be sure it wasnt fibroids, colon CA, appendicitis, pancreatitis etc.....the colonscopy showed the pockets.
Things with "seeds" or hulls and nuts were her triggers. Because usually those things dont digest/break down fully and are easier to get stuck. They recommended she increase her fiber too.
Hugs, its very painful when you flare up.