What are diverticula and diverticulosis?

Diverticula are small pouches that protrude through weak areas of the wall of the large intestine (colon). They may develop anywhere in the colon but are most commonly found in the sigmoid colon, the section of the large bowel located in the lower left side of the abdomen. The presence of diverticula without inflammation is known as diverticulosis.

In most cases, diverticula do not cause any symptoms and are discovered incidentally during a colonoscopy or imaging examination, such as a CT scan.

Diverticulosis does not require treatment unless complications develop. Patients with diverticulosis are advised to reduce the risk of constipation by following a high-fibre diet, maintaining adequate hydration, and engaging in regular physical activity. These measures may help reduce the risk of developing diverticulitis and its complications.

What is diverticulitis?

Diverticulitis is the inflammation of one or more diverticula. It may be uncomplicated (mild) and treated conservatively, or complicated (severe), in which case surgical treatment may be required.

Symptoms

• Pain, usually in the lower left side of the abdomen (the area of the sigmoid colon, where diverticula most commonly occur)
• Changes in bowel habits, such as constipation or diarrhoea
• Tenderness over the affected area of the abdomen
• Occasionally fever, nausea, and vomiting

Diagnosis

• Medical history and clinical examination
• Blood tests (inflammatory markers)
• Computed tomography (CT scan), which is the investigation of choice for confirming the diagnosis and assessing the severity of the disease
• Colonoscopy is generally avoided during the acute phase because of the increased risk of bowel perforation. However, it is recommended 6–8 weeks after complete resolution of symptoms to confirm the diagnosis and exclude other conditions.

Treatment

Treatment depends on the severity of the disease.

In uncomplicated cases, treatment usually consists of oral or intravenous antibiotics, depending on the severity of the infection and a liquid or low-residue diet.

Surgical treatment is reserved for patients with complicated diverticulitis. Surgery may be performed as an emergency or as a planned procedure, depending on the clinical situation. Indications for surgery include:

• Bowel perforation (emergency surgery)
• A large abscess that cannot be successfully treated with image-guided percutaneous drainage
• Recurrent episodes of diverticulitis that significantly impair the patient's quality of life (elective surgery)
• A fistula (an abnormal connection between the bowel and another organ)
• A significant narrowing (stricture) of the bowel

The operation involves removal of the affected segment of the colon containing the diverticula, most commonly the sigmoid colon (sigmoid colectomy). In the majority of patients, the procedure can be performed using a laparoscopic (minimally invasive) approach.