My dad has diverticulitis. what are the causes and how can it be prevented?

Diverticulitis: Diverticulitis is small sacs of intestinal mucosa that are inflamed or infected. Low dietary fiber may be a cause. Straining due to hard stool may increase^ intestinal/colon pressure & ^ sac formation. Medical intervention may be required in more severe cases. Prevention – regular exercise, hydrate well, prevent constipation, avoid refined food, ^’ed fiber intake & adding bulk to diet (psyllium).