Diverticulitis flare-ups occur when the pouches in the colon wall (diverticula) become inflamed or infected. While the exact cause of diverticulitis is unknown, several studies have associated the condition with low fiber intake, excessive alcohol use, and lack of exercise. Some factors that may increase the risk of developing diverticulitis include:

• Aging: The incidence of diverticulitis increases with age.
• Obesity: Being seriously overweight increases the odds of developing diverticulitis.
• Smoking: People who smoke cigarettes are more likely than nonsmokers to experience diverticulitis.
• Lack of exercise: Vigorous exercise appears to lower the risk of diverticulitis.
• Diet high in animal fat and low in fiber: A low-fiber diet in combination with a high intake of animal fat seems to increase the risk, although the role of low fiber alone isnt clear.
• Certain medications: Several drugs are associated with an increased risk of diverticulitis, including steroids, opioids, and nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen sodium.

It was once believed that nuts, seeds, and popcorn could enter or block the diverticula and should be avoided in people with diverticulitis. However, current studies suggest that these foods are high in fiber and may be beneficial in treating the condition. During a diverticulitis flare-up, it is recommended to eat a clear liquid diet for a few days, which consists of liquids through which one can read something. To help prevent recurring flare-ups, a high-fiber diet rich in foods such as bran, whole-wheat pasta, apples, pears, raspberries, beans, sweet potatoes, avocados, and vegetables is recommended, along with regular cardiovascular activity and weight loss if appropriate.