Diverticular disease Flashcards
Define diverticulosis.
Presence of diverticular outpouchings in the colonic mucosa and submucosa through the muscular wall of the large bowel.
Define diverticular disease.
Diverticulosis associated with complications e.g. haemorrhage, infection, fistulae.
Diverticulitis.
Acute inflammation and infection of colonic diverticulae.
What is the pathophysiology of diverticular disease
- Low-fibre diet →
- loss of stool bulk →
- high colonic intraluminal pressures needed to propel stool →
- herniation of the mucosa and submucosa through muscularis which occurs particularly at sites of nutrient artery penetration
Other suggested aetiologies :
- alterations in colonic wall structure (increased type III collagen synthesis, elastin deposition),
- abnormal colonic motility,
- colonic neurotransmitter dysfunction (decreased choline acetyltransferase, increased serotonin expression)
Where are diverticulae most common?
Sigmoid(because of its small diameter) and descending colon but can be right sided
Absent from the rectum
What can result from diverticular obstruction?
Diverticular obstruction by inspissated faeces causes:
- bacterial overgrowth, toxin production,
- mucosal on jury and diverticulitis
- eventually perforation,
- pericolic phlegmon,
- abscess, ulceration
- fistulisation or stricture formation
What are the clinical features of symptomatic diverticular disease?
- EPISODIC - but not every month for example; if so then suspect IBD
- Left-lower abdominal pain
- Colicky pain
- Bloating
- Constipation
- Diarrhoea
However, diverticulosis is mostly asymptomatic and usually incidental finding.
What are the risk factors for diverticular disease?
- Low dietary fibre
- Age >50 years - due to decreasing mechanical strength of the colonic walls. Changes in collagen structure may cause age-associated decreases in the colonic wall strength
- Western diet
- Obesity (BMI >30)
- NSAID use
How common is diverticular disease?
- Diverticulosis in 60% of people
- 70% over 70yrs affected
- Rare <40 years
- Right-sided diverticula are more common in Asia (unknown cause)
What are the clinical features of diverticulosis?
Usually asymptomatic
What are the clinical features of diverticular disease?
- Intermittent
- Altered bowel habit - constipation and diarrhoea
- Colicky left sided abdo pain
- Sometimes rectal bleeding
NB: high fibre diet will minimise symptoms
What are the clinical features of acute diverticulitis?
Uncomplicated:
- Constant LIF pain and tenderness
- Sudden change in bowel habit
- Significant rectal bleeding or mucus passage
- Anorexia, nausea, vomiting
- Diarrhoea
- Pyrexia, raised WCC and CRP
Complicated:
- Abdominal mass, perirectal fullness
- Rigidity/guarding
- Septic
- Fistula signs
- Colicky abdo pain/vomiting (obstruction)
What investigations would you do for diverticular disease?
NB: refer any acute diverticulitis for same-day investigation in secondary care
Initial investigations:
- FBC - polymorphonuclear leukocytosis in acute diverticulitis
- CRP - high
- U&Es - check before requesting contrast CT
- Blood culture
- ABG
- Check clotting and cross-match if bleeding
- CT contrast - thickening of bowel wall, mass, abscess, streaky mesenteric fat; may show gas in the bladder in cases of fistula
- +/- Early colonoscopy/flexible sigmoidoscopy - request if bleeding present, rule out bleeding carcinoma NB: INCREASED RISK OF PERFORATION IN ACUTE DIVERTICULITIS so only request in uncomplicated diverticular disease.
- +/- CXR - ?pneumoperitoneum
Other:
- AXR - pneumoperitoneum, ileus, soft tissue densities; free air in bowel perforation
- US - if CT cannot be obtained - may show abscess, perforation, obstruction
- Diagnostic laparoscopy - consider if primary diagnosis is unclear but there is radiological evidence of significant pathology
What is the management of diverticulosis/diverticular disease?
Asymptomatic - No treatment required - weak evidence for increasing dietary fibre.
Symptomatic -
- Dietary modification and fibre supplementation
- Oral antibiotic therapy
What is the management of acute diverticulitis?
Uncomplicated
- Analgesia
- Oral antibiotic e.g. amoxicillin for 4-10days; or IV antibiotic if no improvement after 72hrs - e.g. ceftriaxone and metronidazole
- Low-residue diet e.g. refined bread, cereals, white rice, vegetable and fruit juice without pulp, dairy products
Complicated
- NBM
- IV fluids and antibiotics
- Analgesia - avoid opioids
- Surgery if major haemorrhage or perforation; abscesses >3cm can be drained under CT/US guidance.
- Low-residue diet
Recurrent:
-
Surgery - no set criteria and not based on number of previous attacks alone.
- Hartmann’s procedure - resection and stoma
- One-stage resection and anastomosis
- Laparoscopic drainage, peritoneal lavage and drain placement can also be effective
What is shown below?
- Normal appearances
- Enhancing high-density mass in left iliac fossa in keeping with an aneurysm
- Thick walled mass containing air and fluid suggestive of an abscess in left iliac fossa with thick walled bowel loop adjacent.
- Large mass in pelvis suggestive of ovarian carcinoma
Thick walled mass containing air and fluid suggestive of an abscess in left iliac fossa with thick walled bowel loop adjacent.
What is Hartmann’s procedure?
