Diverticular disease

Diverticulosis is a digestive condition characterised by small pouches (diverticula) that protrude from the walls of the large intestine.

A diverticulum is an outpouching of the colonic wall that classically forms “pockets” (1).

• formed when colonic mucosa and submucosa herniates through defects in the circular muscle layer of the colonic wall (where blood vessels penetrates the colonic wall to supply the mucosa) (1)
• can be seen throughout the colon, but more common in the sigmoid colon (2)
• may vary from a single diverticulum to many hundreds (diverticulae)
• diameter is usually 5-10 mm but may exceed 2 cm (3)
• acquired diverticulae appear in the colon, especially the sigmoid colon, probably as a result of changes in bowel motility and the consistency of the faeces. Many believe that the condition is caused solely by the Western diet with its low roughage content.

Diverticulosis (presence of diverticulae) may be:

• asymptomatic - absence of any symptom or complications of the disease, frequently an incidental finding
• symptomatic or diverticular disease – clinically significant and symptomatic diverticulosis
  • uncomplicated diverticular disease – patients with symptoms, but without signs of diverticular inflammation
    • recurrent symptomatic diverticular disease - patients with diverticulae who experience recurrent symptoms (more than 1 attack per year) but without signs of diverticular inflammation
  • complicated diverticular disease – patients with symptoms and demonstrate signs of diverticular inflammation with further complications (haemorrhage, abscess, phlegmon, perforation, purulent and faecal peritonitis, strictures, fistulas) (1,4,5)

The true prevalence of diverticulosis is difficult to determine because most patients are asymptomatic (6):

• it is age dependent and relatively uncommon in people aged under 40, although in recent years there has been a dramatic rise in the prevalence in this age group. In people aged over 65 the prevalence is up to 65%
• about 80 to 85% of people affected by diverticulosis remain asymptomatic, and 10 to 15% develop symptomatic diverticular disease including acute diverticulitis and its complications (perforation, abscess formation, haemorrhage, fistula and obstruction).

NICE suggest that a clinician should suspect diverticular disease if a person presents with one or both of the following (6):

• intermittent abdominal pain in the left lower quadrant with constipation, diarrhoea or occasional large rectal bleeds (the pain may be triggered by eating and relieved by the passage of stool or flatus)
  
  
• tenderness in the left lower quadrant on abdominal examination

• be aware that:
  • in a minority of people and in people of Asian origin, pain and tenderness may be localised in the right lower quadrant
  • symptoms may overlap with conditions such as irritable bowel syndrome, colitis and malignancy

Reference

1. Feuerstein JD, Falchuk KR. Diverticulosis and Diverticulitis. Mayo Clin Proc. 2016 Aug;91(8):1094-104
2. Peery AF, Sandler RS. Diverticular disease: reconsidering conventional wisdom. Clin Gastroenterol Hepatol. 2013;11(12):1532-7.
3. Stollman N, Raskin JB. Diverticular disease of the colon. Lancet. 2004;363(9409):631-9.
4. Tursi A. Diverticular disease: A therapeutic overview. World Journal of Gastrointestinal Pharmacology and Therapeutics. 2010;1(1):27-35.
5. Janes SE et al. Management of diverticulitis. BMJ 2006;332:271-5.
6. NICE (November 2019). Diverticular disease: diagnosis and management