Diverticular disease Flashcards
What is diverticular disease?
- Any clinical state caused by symptoms pertaining to colonic diverticula (outpouching of the colonic mucosa on the outside of the colon)
- Diverticulosis → presence of diverticula inside the colon. Usually don’t cause symptoms and don’t need to be treated. May have blood in stools. Can lead to diverticulitis.
- Diverticular Disease → symptomatic diverticulosis associated with complications (haemorrhage, infection)
- Diverticulitis → inflammation in one or more of the diverticula (get fever, malaise etc) - Most commonly found in sigmoid colon and then descending colon
What are the risk factors for diverticular disease?
age >50 yrs (decreased mechanical strength of colonic walls), low dietary fibre, constipation, diet rich in salt + meat + sugar, obesity, NSAID & Opioid use, smoking
What classification is used to stage diverticular disease?
Hinchey Classification of Acute Diverticulitis
- Ia: phlegmon (tissue necrosis and the absence of a capsule or boundaries of the lesion)
- Ib and II: localised abscesses
- III: perforation and purulent peritonitis
- IV: faecal peritonitis
What causes diverticular disease?
- A low-fibre diet leads to loss of stool bulk. This leads to 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 muscle layers of the gut at weak points adjacent to penetrating vessels.
Describe the pathogenesis of diverticular disease
- 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
- Diverticulae 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
Summarise the epidemiology of diverticular disease
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
What are the presenting symptoms of diverticular disease?
- 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-gas in the urine, faecaluria and recurrent UTI)
What signs of diverticular disease can be found on physical examination?
- Diverticulitis - tender abdomen and signs of local or generalised peritonitis if a diverticulum has perforated
- Commonly is an incidental finding at colonoscopy
What investigations are used to diagnose/ monitor diverticular disease?
- Contrast CT scan of Abdomen → request in patients with suspected acute diverticulitis and raised inflammatory markers
- Perforation -erect CXR (pneumoperitoneum and Rigler’s sign - AXR)
- Colonoscopy → visualise diverticula and other pathology (e.g. polyps and tumours) can be excluded
- FBC (Diverticulitis) → high - WCC, high CRP
- Barium Enema → 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 - U&E → assess kidney function to determine whether contrast CT can be performed
How is diverticular disease managed?
- Asymptomatic Diverticulosis → dietary & lifestyle modifications (ie. increase dietary fibre and fluids)
- Symptomatic Diverticular Disease → increase dietary fibre
- Acute Diverticulitis (uncomplicated) → oral antibiotics and analgesia. If not resolved within 72hrs admit for IV antibiotics (ceftriaxone + metronidazole).
- Surgery if recurrent attacks or complications (abscess, perforation, fistulae, obstruction) → Hartmann’s Procedure (resection of rectosigmoid colon and end colostomy is formed).
What complications may arise from diverticular disease?
- Abscess (require CT-guided drainage), perforation (need urgent laparotomy), strictures (can lead to large bowel obstruction), fistula formation
- Pneumaturia (air/gas in urine) or faecaluria and recurrent UTIs may suggest a colovesical fistula. Vaginal passage of faeces or flatus may suggest a colovaginal fistula.
