What is the diagnosis and treatment for diverticulitis (inflammation of the diverticula)?

From the Guidelines

Diverticulitis should be diagnosed using abdominal CT imaging when there is diagnostic uncertainty, and most patients with acute uncomplicated left-sided colonic diverticulitis can be managed in an outpatient setting without antibiotics, unless they have comorbidities, are frail, or present with refractory symptoms or vomiting. The diagnosis of diverticulitis involves a detailed history, physical examination, and laboratory findings, and abdominal CT imaging can be used to complement these findings when there is diagnostic uncertainty 1. The management of diverticulitis depends on the severity of the disease, with mild cases often managed at home with oral antibiotics, clear liquid diet, and gradual return to normal eating as symptoms improve. Some key points to consider in the management of diverticulitis include:

• The use of antibiotics should be selective, rather than routine, in immunocompetent patients with mild uncomplicated diverticulitis 1.
• Immunocompromised patients are more likely to present with severe or complicated disease and should be treated with antibiotics and considered for consultation with a colorectal surgeon 1.
• Patients with uncomplicated diverticulitis who are immunosuppressed are high risk for progression to complicated diverticulitis and/or sepsis and should be treated with antibiotics 1.
• The antibiotic regimen usually includes broad spectrum agents with gram-negative and anaerobic coverage, such as amoxicillin-clavulanate or ciprofloxacin plus metronidazole, and the duration of treatment is usually 7-10 days, but can be longer in immunocompromised patients 1.
• Pain can be managed with acetaminophen or, if needed, prescription pain medication, and severe cases require hospitalization for IV antibiotics, bowel rest, and possibly surgery.
• To prevent recurrence, patients should maintain a high-fiber diet, stay well-hydrated, exercise regularly, and avoid constipation. Risk factors for diverticulitis include age over 40, low-fiber diet, obesity, smoking, and certain medications like NSAIDs, and warning signs such as severe abdominal pain, fever, nausea, vomiting, or changes in bowel habits require prompt medical attention. In terms of specific management strategies, the American College of Physicians (ACP) suggests that clinicians use abdominal CT imaging when there is diagnostic uncertainty in a patient with suspected acute left-sided colonic diverticulitis, and manage most patients with acute uncomplicated left-sided colonic diverticulitis in an outpatient setting without antibiotics, unless they have comorbidities, are frail, or present with refractory symptoms or vomiting 1. Overall, the management of diverticulitis should be individualized based on the severity of the disease, the presence of comorbidities, and the patient's overall health status, and should involve a multidisciplinary approach, including primary care physicians, gastroenterologists, and colorectal surgeons.

From the Research

Diagnosis and Classification of Diverticulitis

• Radiological evidence of inflammation, using computed tomography (CT), is needed to diagnose the first occurrence of diverticulitis 2
• CT is also warranted when the severity of symptoms suggests that perforation or abscesses have occurred 2
• Diverticulitis is classified as complicated or uncomplicated based on CT scan, severity of symptoms and patient history; this classification is used to direct management 2

Treatment of Uncomplicated Diverticulitis

• Outpatient treatment is recommended in afebrile, clinically stable patients with uncomplicated diverticulitis 2
• Antibiotics have no proven benefit in reducing the duration of the disease or preventing recurrence, and should only be used selectively 2, 3
• A systematic review and meta-analysis found that patients with uncomplicated diverticulitis can be monitored off antibiotics 3
• Outpatient treatment for uncomplicated diverticulitis is feasible and safe, with a lower failure rate compared to inpatient treatment 4

Treatment of Complicated Diverticulitis

• Non-operative management, including bowel rest and intravenous antibiotics, is indicated for small abscesses 2
• Larger abscesses of 3-5 cm should be drained percutaneously 2
• Patients with peritonitis and sepsis should receive fluid resuscitation, rapid antibiotic administration and urgent surgery 2
• Surgical intervention with either Hartmann procedure or primary anastomosis, with or without diverting loop ileostomy, is indicated for peritonitis or in failure of non-operative management 2

Role of Antibiotics in Diverticulitis

• Antibiotics are routinely used for diverticulitis irrespective of severity, but current practice guidelines favor against the use of antibiotics for acute uncomplicated diverticulitis 3
• Rifaximin has demonstrated to be effective in obtaining symptoms relief at 1 year in patients with uncomplicated diverticular disease and to improve symptoms and maintain periods of remission following acute colonic diverticulitis 5
• Antibiotics seem to remain the mainstay of treatment in symptomatic uncomplicated diverticular disease and acute diverticulitis 5