Definition
Diverticula are small sac-like protrusions that form in the walls of the digestive tract, usually in the colon. When accompanied by inflammation, the condition is called diverticulitis.

Pathogenesis
The development of diverticula is associated with increased pressure inside the intestine, due to low fiber intake or chronic constipation. Inflammation in diverticula can result from trapped stool or microtrauma.

Diagnosis
Diagnosis is usually made with colonoscopy or imaging tests such as CT scans. In cases of acute inflammation, clinical symptoms like lower left abdominal pain and fever are indicative.

Treatment
Management depends on the severity of the condition. For asymptomatic diverticula, dietary changes with increased fiber intake are recommended. In cases of diverticulitis, antibiotics are used, and in severe cases, surgery may be necessary. Ongoing monitoring helps prevent recurrences and complications.

Key figures: Prevalence rises markedly with age. Colonoscopy is not performed during the acute episode but 6 to 8 weeks after it settles, to avoid perforation and to exclude a neoplasm.

A low fibre diet and chronic constipation are contributing factors. After the acute episode settles, colonoscopy serves to exclude colorectal cancer.

Key figures

  • Colonoscopy is performed 6 to 8 weeks after the acute episode
  • Nuts and seeds do not need to be avoided
  • Mild uncomplicated diverticulitis may not require antibiotics
  • Diverticular bleeding is typically painless

Frequently asked questions

Should I avoid nuts and seeds?

No. This was standard advice for decades, on the theory that small particles lodge in diverticula and cause inflammation. The evidence did not support it and the recommendation has been abandoned. A diet rich in fibre, which includes nuts, is beneficial.

Are antibiotics always needed for diverticulitis?

Not any longer. In mild, uncomplicated diverticulitis and in selected patients without aggravating factors, management can proceed without antibiotics, using diet, analgesia and close follow up. Antibiotics remain essential in complicated disease. The decision is individualised.

Why is colonoscopy not done straight away?

Because during acute inflammation the bowel wall is vulnerable and the examination increases the risk of perforation. CT is the investigation of choice in the acute phase. Colonoscopy is scheduled after resolution, typically six to eight weeks later, and matters because it excludes a neoplasm that can produce a similar picture.

Is diverticular bleeding painful?

Characteristically not. It presents as sudden, painless passage of a significant amount of blood from the rectum, and usually occurs without inflammation being present. It is one of the commonest causes of lower gastrointestinal bleeding and requires prompt medical assessment even if it stops on its own.

Sources


Content last updated: September 2026 (14/09/2026).