Definition/diagnostic criteria Diverticular disease encompasses a spectrum of conditions related to the presence of diverticula, which are small pouches or bulges developing in the lining of the intestine. Diverticulosis refers to the presence of these diverticula without associated inflammation or symptoms. When these pouches become inflamed or infected, it leads to diverticulitis. The diagnosis typically relies on clinical features supported by investigation findings.
Epidemiology Diverticular disease is common in Western countries, with a prevalence that increases with age. In the UK, about half of the population aged over 50 years and two-thirds over 80 years have diverticulosis. However, only a minority develop symptomatic diverticular disease or diverticulitis. Lifestyle factors, such as a low-fibre diet, are thought to contribute to its development.
Clinical features: Symptoms of diverticular disease can vary. Diverticulosis is often asymptomatic, discovered incidentally during investigations for other conditions. Symptomatic diverticular disease typically presents with abdominal pain, usually in the lower left quadrant, and may be associated with alterations in bowel habits. Complicated diverticulitis can present with signs of infection or peritonitis. Diverticular disease can also lead to haemorrhage (in about 15% of patients), which can be significant.
Investigations: This will depend on the clinical scenario but typically might include blood tests, faecal calprotectin and a FIT test. Confirmation of diagnosis requires specialised investigation such as colonoscopy or computed tomography (CT) colonography (which may be done to exclude other potential diagnoses such as colonic cancer).
Treatment Asymptomatic diverticular disease just requires advice around a healthy diet. A gradual increase in fibre is advised if constipation is a problem. Uncomplicated diverticular disease causing symptoms such as recurrent spasmodic abdominal pain may require dietary advice, a laxative and/or anti-spasmodics.
Mild cases of diverticulitis require advice and analgesia (avoiding NSAIDs and ideally opioids). In more severe cases, antibiotics (such as co-amoxiclav) or admission will be required.
For recurrent or severe cases, elective surgery may be considered (particularly in the presence of complications such as a stricture or fistula).
Prognosis The majority of patients with diverticular disease have a favourable prognosis. Symptomatic improvement typically occurs within a few days of appropriate management. However, about 20% of patients with an episode of acute diverticulitis may have recurrent episodes. The risk of complications, such as abscess formation, fistula or perforation, increases with the severity of the disease.