B-Quick: Diverticulitis

Diverticulitis: B-QuiCK

Most patients with diverticulosis are asymptomatic; approximately 4% will develop diverticulitis.

Clinical features of diverticulitis include new-onset abdominal pain (often lower left quadrant), recent changes in bowel habit, nausea, anorexia, bloating, flatulence and fever.

• Rectal bleeding is rare in acute diverticulitis
• Do not rule out diverticulitis in patients presenting with right-sided abdominal pain, especially those of Asian or African ethnicity

For patients with symptoms indicative of diverticulitis in primary care, clinicians should:

• Consider if there is a history of diverticulosis (and diverticulitis)
  • Ask about pain characteristics, recent use of medicines, family history
• Perform a physical examination and consider relevant investigations, e.g. full blood count, CRP, urinalysis and stool culture (if diarrhoea is a predominant feature)
• Assess for red flag symptoms suggesting complications:
  • Sepsis, e.g. fever, pallor, systolic hypotension, tachycardia, elevated respiratory rate, altered mental state, reduced urine output
  • Intra-abdominal abscess, e.g. palpable abdominal mass or peri-rectal fullness on rectal examination, severe pain, fever, abdominal rigidity and voluntary guarding
  • Intestinal obstruction, e.g. severe pain, vomiting, constipation (or obstipation) and abdominal distention
  • Bowel perforation or peritonitis, e.g. severe pain, fever, abdominal rigidity and voluntary guarding
  • Evidence of a fistula from the colon to the bladder (e.g. faecaluria, pneumaturia, pyuria), or vagina (e.g. passage of gas or faeces through the vagina)
• Consider differential diagnoses, e.g. appendicitis, inflammatory bowel disease, irritable bowel syndrome, colorectal cancer

If a working diagnosis of diverticulitis is made:

Is the patient well enough to be managed in the community?

• Home management is usually not appropriate for patients with:
  • Symptoms suggestive of complicated diverticulitis or systemic infection
  • Significant or uncontrolled co-morbidities, or other risk factors
  • No support at home (or who are unable to independently seek medical attention if symptoms do not improve)
  • Difficulty tolerating oral fluids or controlling pain
• Initiate conservative treatment if community management is appropriate:
  • Prescribe paracetamol (NSAIDs or weak opioids can be considered if no contraindications)
  • If tolerated, patients should continue to follow an unrestricted diet
    • Some patients may prefer a short-term clear liquid diet
  • Give clear advice regarding red flag symptoms that would prompt presentation to the emergency department, e.g. increasing abdominal pain, ongoing vomiting, persistently elevated fever, inability to eat, per rectum bleeding
• Oral antibiotics are not required at initial presentation for most patients with suspected acute uncomplicated diverticulitis and mild symptoms
  • Use clinical judgement to determine which patients may benefit from antibiotics, e.g. those at higher risk of complications, taking certain medicines (such as corticosteroids, anticoagulants) or systemically unwell but not meeting local criteria for hospital referral

• Antibiotic regimens for adult patients with suspected acute uncomplicated diverticulitis

  First-line dual treatment
  Metronidazole		400 mg, three times daily, for five or seven days*
  PLUS, ONE OF EITHER:
  	Trimethoprim + sulfamethoxazole	960 mg, twice daily, for five days
  	Amoxicillin	500 mg, three times daily, for seven days
  	Cefalexin	500 mg, two to three times daily (maximum 1 – 1.5 g, three to four times daily), for five days
  Alternative monotherapy:
  Amoxicillin + clavulanic acid		Adult: 625 mg, three times daily, for five days

  ^*Give seven days course of metronidazole if prescribed with amoxicillin

• Ideally, reassess the patient after 48 hours (or sooner if indicated); oral antibiotics can be considered again at this point if the patient’s condition has not improved but they still do not require secondary care referral
  • Refer the patient to secondary care if red flag symptoms develop during community management or if there is an inadequate response to treatment following the initiation of oral antibiotics

Follow-up:

Approximately 5% of patients with diverticulitis will develop complications, e.g. perforation or abscess, usually within ten days of their initial presentation (can be up to three months later). Potential predictors for progression to complicated diverticulitis:

• Symptoms persisting for longer than five days
• Vomiting
• Significantly elevated CRP, i.e. > 140 mg/L
• Leukocytosis, i.e. > 13.5 x 10⁹ cells/L

In patients who have recovered from acute diverticulitis, the goal of ongoing management is to prevent future episodes. Recommended lifestyle modifications^* including increasing dietary fibre, limiting red meat, maintaining adequate hydration, weight loss and increasing physical activity, smoking cessation and avoiding use of over-the-counter NSAIDs.

^* Recommendations also apply to patients with diverticulosis to prevent the initial development of diverticulitis

Chronic diverticulitis is when patients experience ongoing gastrointestinal symptoms, lasting at least three months despite treatment with oral antibiotics; discuss with a gastroenterologist (in rare cases, patients may be considered for surgical treatment).

Colonoscopy may be indicated. Appropriate follow-up of patients with diverticulitis is crucial to rule out colorectal cancer:

• Patients with complicated, CT-proven diverticulitis require a colonoscopy – this should not be performed for at least six weeks after resolution of symptoms due to risks of bowel perforation
• Patients with uncomplicated, CT-proven diverticulitis do not require a colonoscopy (a CT scan is sufficient in most cases)
• In patients with suspected, uncomplicated diverticulitis (who have not received a CT scan), refer for colonoscopy if other risk factors are present