Actually, no specific foods are known to trigger a diverticulitis attack. And there's no diverticulitis diet that's been proven to prevent attacks.
Still, following a so-called diverticulitis diet remains a popular, if unproven, way to try to prevent or treat diverticulitis attacks. Nuts, seeds and popcorn were once discouraged under a diverticulitis diet because they were said to trigger diverticulitis attacks. But research shows that seeds and popcorn don't increase the risk of diverticulitis or diverticular bleeding, so it's OK to eat them even if you have diverticulosis.
If you're trying to prevent diverticulitis attacks, focus less on a so-called diverticulitis diet and more on an overall healthy diet that's high in fiber. High-fiber foods, such as fruits, vegetables and whole grains, soften waste and help it pass more quickly through your colon. This reduces pressure within your digestive tract, which can reduce the risk of diverticulitis attacks.
If you think that you're having a diverticulitis attack, talk to your doctor. Your doctor will likely prescribe treatment and suggest that you follow a clear-liquid diet for two or three days, and then gradually add in low-fiber foods. This kind of diverticulitis diet helps your digestive tract rest and heal during treatment.