Experts are not sure what causes diverticulosis and diverticulitis. Researchers are studying several factors that may play a role in causing these conditions.

1. Fiber
For more than 50 years, experts thought that following a low-fiber diet led to diverticulosis. However, recent research has found that a low-fiber diet may not play a role. This study also found that a high-fiber diet with more frequent bowel movements may be linked with a greater chance of having diverticulosis.4 Talk with your doctor about how much fiber you should include in your diet.

2. Genes
Some studies suggest that genes may make some people more likely to develop diverticulosis and diverticulitis. Experts are still studying the role genes play in causing these conditions.

3. Other factors
Studies have found links between diverticular disease-diverticulosis that causes symptoms or problems such as diverticular bleeding or diverticulitis-and the following factors:
__certain medicines-including nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin , and steroids
__lack of exercise
__obesity
__smoking

Diverticulitis may begin when bacteria or stool get caught in a pouch in your colon. A decrease in healthy bacteria and an increase in disease-causing bacteria in your colon may also lead to diverticulitis.