Diverticular Disease

Question 1

Define

Answer 1

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 inflammation and infection of colonic diverticulae

Hinchey Classification of Acute Diverticulitis:

• Ia: phlegmon
• Ib and II: localised abscesses
• III: perforation and purulent peritonitis
• IV: faecal peritonitis

Question 2

Causes

Answer 2

Aetiology:

• A low-fibre diet leads to loss of stool bulk
• This leads to the generation of high colonic intraluminal pressures to propel the stool out
• This, in turn, leads to the herniation of the mucosa and submucosa through the muscularis

Pathogenesis:

• Diveticulae are most commonly found in the sigmoid and descending colon
• However, they can also be right-sided
• Diverticulae are NOT found in the rectum
• Diverticular are found particularly at sites of nutrient artery penetration
• Diverticular obstruction by thickened faeces can lead to bacterial overgrowth, toxin production and mucosal injury
• Which can then lead to diverticulitis, perforation, pericolic phlegmon, abscess, ulceration and fistulation or stricture formation

Question 3

Epidemilogy

Answer 3

Diverticular disease is VERY COMMON

60% of people living in industrialised countries will develop colonic diverticulae

Rare < 40 yrs

Right-sided diverticulae are more common in Asia

Question 4

Symptoms

Answer 4

Often ASYMPTOMATIC (80-90%)

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

Signs

Answer 5

Diverticulitis - tender abdomen and signs of local or generalised peritonitis if a diverticulum has perforated

Question 6

Investigations

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)
• This reflects pseudohypertrohy of circular muscle
• IMPORTANT: barium enema should NOT be performed in the acute setting because there is a high risk of perforation

Flexible Sigmoidoscopy and Colonoscopy:

• Diverticulae can be visualised 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

Management

Answer 7

Asymptomatic:

• Soluble high-fibre diet (20-30 g/day)
• Some drugs are under investigation for their use in preventing recurrent flares of diverticulitis (such as probiotics and anti-inflammatories)

GI Bleed:

• PR bleeding usually managed conservatively with IV rehydration, antibiotics and blood transfusion if necessary
• Angiography and embolisation or surgery if severe

Diverticulitis:

• IV antibiotics
• IV fluid rehydration
• Bowel rest
• Abscesses ma 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

Complications

Answer 8

Diverticulitis

Pericolic abscess

Perforation

Faecal peritonitis

Colonic obstruction

Fistula formation (bladder, small intestine, vagina)

Haemorrhage

Question 9

Prognosis

Answer 9

10-25% have one or more episodes of diverticulitis