Diverticulitis is a gastrointestinal disorder characterized by the formation of small pockets, or "diverticula," in the lining of the intestines and colon. Although common, research still needs to be done to determine the exact causes of this ailment.What Causes Diverticulitis?As noted above, many Americans develop diverticulitis as they age. Research indicates that the formation of diverticula may be associated with increased intake of processed food. Diverticulitis was first noticed around 1900, which coincides with the time that many Americans began consuming larger quantities of processed food. Another factor may be a diet low in fiber. The disease is common in America and other Western nations that consume low fiber diets, but rare in Africa and Asia, where more fiber is consumed. Some researchers speculate that a diet low in fiber results in frequent constipation. The pressure caused by this constipation weakens the gastrointestinal tract, allowing pockets to form.Symptoms of DiverticulitisMany people are not even aware that they possess this disorder. Diverticulitis can remain dormant, never causing any problems. Alternatively, it can cause flares, or bouts of pain, at any time. Symptoms of a flare include constipation, bloating, bleeding, and fistulas.Diverticulitis DietDoctors used to recommend a diet low in fiber for patients diagnosed with diverticulitis. The theory was that fibrous materials, such as seeds and nuts, could get stuck in the diverticula and cause pain. However, more recent research indicates that this disorder is caused by a lack of dietary fiber. As such, doctors recommend that patients with this order consume a diet high in fiber, unless specific foods trigger a flare.Eating During a FlareAs noted above, diverticulitis should not typically limit fiber consumption. However, the gastrointestinal tract becomes inflamed during a flare, and the diet must be adjusted accordingly. To soothe the stomach at this time, most doctors suggest patients go on a clear, liquid diet for a few days. Following this, easy to digest foods, such as bananas, toast, and cooked vegetables, can be consumed. Patients should consult a doctor before beginning any diet to treat this disorder.