Diverticular disease

Question 1

Define diverticular disease.

Answer 1

When discussing patients with diverticular disease it is important to distinguish between the following terms.

• Diverticulosis: the presence of diverticulae outpouchings of the colonic mucosa and submucosa through the muscular wall of the large bowel
• Diverticular disease: diverticulosis associated with complications e.g. haemorrhage, infection, fistulae
• Diverticulitis: acute classification of acute diverticulitis.
• Hinchey classification of acute diverticulitis:
  >Ia: phlegmon
  >Ib and II: localised abscesses purulent peritonitis
  >IV: faecal peritonitis

Question 2

Summarise the aetiology of diverticular disease.

Answer 2

Aetiology: low-fibre diet leads to loss of stool bulk leading to the generation of high colonic intraluminal pressures to propel the stool out. This leads to the herniation of the mucosa and submucosa through the muscularis.

Pathogenesis: Most common in the sigmoid and descending colon, they can also be right sided but never in the rectum. Diverticulae are found particularly at sites of nutrient artery penetration. Diverticulae obstruction by thickened faeces ——> bacterial overgrowth ——> toxin overgrowth and mucosal injury.
This can lead to diverticulitis, perforation, pericolic phlegmon, abscess, ulceration and fistulation or stricture formation

Question 3

Summarise the epidemiology of diverticular disease

Answer 3

• Very common
• 60% of people living in industrialised countries will develop colonic diverticulae
• Rare<40yrs
• Right sided diverticulae are more common in Asia

Question 4

Describe the history/presenting symptoms of diverticular disease

Answer 4

• 80-90% of cases are asymptomatic.
• Complications can lead to symptoms such as:
  >PR bleeding
  >Diverticulitis causing LIF and lower abdominal pain and fever.
  >Diverticular fistulation causing pneumaturia, faecaluria and recurrent UTI.

Question 5

What are the signs of diverticular disease upon physical examination?

Answer 5

Diverticulitis presents with tender abdomen and signs of local or generalised peritonitis if a diverticulum has perforated.

Question 6

What investigations are used to identify diverticular disease?

Answer 6

• Bloods: FBC (increased WCC, increased CRP), check clotting and cross-match if bleeding.
• Barium enema (with or without air contrast): shows presence of diverticulae (saw-tooth appearance of lumen), reflects pseudo hypertrophy of circular muscle. Should NOT be performed in the acute setting.
• Flexible sigmoidoscopy and colonoscopy: Diverticulae can be visualized and other pathology (e.g. polyps and tumours) can be excluded.
• In acute setting: CT scan for evidence of diverticular disease and complications may be performed.

Question 7

How is diverticular disease managed?

Answer 7

• Asymptomatic: Soluble high-fibre diet (20/30g/day), some drugs under investigation in preventing recurrent flares of diverticulitis e.g. probiotics + anti-inflammatory.
• GI bleed: PR bleeding usually managed conservatively with IV rehydration, antibiotics + if necessary blood transfusion. If severe, angiography and embolization or surgery if severe.
• Diverticulitis: IV antibiotics, IV fluid rehydration, bowel rest, abscesses may be drained by radiologically sited drains.
• Surgery: May be necessary in patients with recurrent attacks or complications (e.g. perforation and peritonitis)
• Open surgery:
  > Hartmann’s procedure (proctosigmoidectomy leaving a stoma)
  > One-stage resection and anastomosis (risk of leak) - with or without defunctioning stoma.
• Laparoscopic drainage, peritoneal lavage and drain placement can be effective

Question 8

What are the complications of diverticular disease?

Answer 8

• Diverticulitis
• Pericolic abscess
• Perforation
• Faecal peritonitis
• Colonic obstruction
• Fistula formation (bladder, small intestine, vagina)
• Haemorrhage

Question 9

Summarise the prognosis for patients with diverticular disease

Answer 9

10-25% have one or more episodes of diverticulitis.