Diverticulae can occur throughout the gastrointestinal tract but are more common in the sigmoid & descending colon. Whilst frequently found, usually, it is incidental and not contributing to the presentation of the patient in front of you. In this article, we will take you through the spectrum of presentations & give an overview of the assessment and management.

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Definitions

• Diverticulosis – herniation of mucosa and submucosa through the muscularis
• Diverticulum – a single outpouching
• Diverticular disease – any clinical state caused by symptoms pertaining to colonic diverticulae 
• Diverticulitis – indicates inflammation of a diverticulum and is the cause for acute presentations

Epidemiology

• 10% of people <40
• 50% of people >50
• M = F
• Mostly affects the sigmoid colon
• Asian ethnicities have higher incidences of right sided disease
• Rectal diverticulum extremely rare

Risk Factors

• Low fibre diet 
• Age
• Decreased physical activity 
• Obesity 
• Smoking
• Alcohol 
• NSAIDs
• Genetics (EDS, Marfan’s, Adult polycystic kidney disease)

Spectrum of Presentation

• Incidental diverticulosis (e.g. visible on CT scan) = asymptomatic
• Uncomplicated diverticulitis = LLQ pain, change in bowel habit, fever, LGI bleed, abdominal mass
• Complicated diverticulitis = as above +/- peritonitis (rigidity, guarding, shock) +/- fistulas

Hinchey Classification

• Stage 1 = localised pericolic abscess
• Stage 2 = large pericolic or mesenteric abscess
• Stage 3 = small perforation (small amount of gas/liquid escaping into abdomen)
• Stage 4 = large perforation (faeces escaping into abdomen)

Common Complications

• Abscess = wall off collection of pus
• Perforation = hole to the bowel wall
• Bleed
• Sepsis
• Fistula = abnormal connection between two epithelial surfaces (e.g. bowel to bladder aka colo-vesicular fistula)
• Obstruction = blockage of large bowel due to a diverticular stricture (narrowing)
• Phlegmon = a non-walled off collection of pus +/- inflamed soft tissue

Investigations

• Bedside: ECG, COVID test, Urine dip, Urine HcG, PR examination
• Bloods: FBC, U/E, LFT, CRP, Mg, Bone profile, G&S, Clotting
• Radiology: Erect CXR + AXR, dedicated USS, CTAP with contrast (gold standard), CT angiogram (if finding a large diverticular bleed)

Management

• Conservative
  • Nausea and vomiting à Ondansetron, cyclizine
  • Pain à Paracetamol, tramadol, oramorph, buscopan
  • Lifestyle advice à Increase fibre, exercise, less smoking/alcohol, hydration, ispaghula husk, avoid NSAIDs
  • No antibiotics if: systemically well with mild pain, not immunosuppressed with no significant comorbidities
  • Diverticular bleeds are often Mx conservatively
• Medical
  • Antibiotics (consult local guidelines)
    • Uncomplicated diverticulitis à oral co-amoxiclav 5d
    • Complicated diverticulitis à IV co-amoxiclav
  • Sepsis à Sepsis 6 +/- early ITU input
  • Thromboprophylaxis: Prophylactic LMWH, BD if overweight, hold if surgery
  • Interventional radiology
    • Drainage of pericolic abscesses >3cm
    • Coiling of large diverticular bleeds
  • Surgical
    • Elective surgery
      • Previous episode of complicated disease and recovered with ongoing Sx (fistula, stricture)
    • Emergency surgery
      • Hartmann’s procedure if faecal peritonitis/ large perforation/ bowel ischaemia/ obstruction

Prognosis

• Most patients have a single episode of uncomplicated diverticulitis
  • Medical management
• One third have a recurrence in 5 years
  • Risk higher in abscess formation and young patients
  • Recurrent disease has higher mortality
• Only 1 in 4 patients that have surgery remain symptom free
• Follow up
  • Clinic appointment for colonoscopy once settled to rule out cancer (many meet the 2WW criteria e.g. bleeding/change in bowel habit)

Written by Dr Marc Huttman (FY2)