Diverticulitis, also called colonic diverticulitis, is a digestive disease in which pouches within the large bowel wall become inflamed. Symptoms typically include lower abdominal pain of a sudden onset. The onset of symptoms, however, may also occur over a few days. In North America and Europe pain is usually on the left side, while in Asia it is often on the right. There may also be fever, nausea, diarrhea or constipation, or blood in the stool. Repeated attacks may occur.
The causes of diverticulitis are uncertain. Risk factors may include obesity, lack of exercise, smoking, a family history of the disease, and nonsteroidal anti-inflammatory drugs (NSAIDs). The role of dietary fibre is unclear. Having pouches in the large intestine that are not inflamed is known as diverticulosis. Inflammation occurs in between 10% and 25% at some point in time and is due to a bacterial infection. Diagnosis may be made by blood tests, CT scan, colonoscopy, or lower gastrointestinal series. The differential diagnosis includes irritable bowel syndrome.
While the avoidance of nuts and seeds has historically been recommended, no association between eating these foods and diverticulitis has been found, and therefore, avoiding these foods is no longer recommended. Mesalazine and rifaximin appear useful for preventing attacks in those with diverticulosis. For mild diverticulitis, antibiotics by mouth and a liquid diet is recommended. For severe cases, intravenous antibiotics, hospital admission, and complete bowel rest may be recommended. Probiotics are of unclear use. Complications such as abscess formation, fistula formation, and perforation of the colon may require surgery.
The disease is common in the Western world and uncommon in Africa and Asia. In the Western world about 35% of people have diverticulosis while it affects less than 1% of those in rural Africa, and 4 to 15% of those may go on to develop diverticulitis. The disease becomes more frequent with age, being particularly common in those over the age of 50. It has also become more common in all parts of the world.