Diverticulitis

Importance: Diverticulosis is defined by the presence of multiple outpouchings (diverticula) originating from the intestinal lumen. Diverticulitis is defined as inflammation of these diverticula. The annual incidence of diverticulitis in the US is approximately 180 per 100 000 people, resulting in approximately 200 000 hospital admissions annually and an estimated health care expenditure of more than $6.3 billion/year. Observations: Risk factors for diverticular disease include age older than 65 years, genetic factors such as variant in the tumor necrosis factor superfamily member 15 (TNFSFI5) gene; connective tissue diseases such as polycystic kidney disease, Marfan syndrome, or Ehlers-Danlos syndrome; body mass index 30 or greater; use of opioids, steroids, and nonsteroidal anti-inflammatory medications; hypertension; and type 2 diabetes. Approximately 1% to 4% of patients with diverticulosis will develop acute diverticulitis in their lifetime, which typically presents as left lower quadrant pain associated with nausea, vomiting, fever, and leukocytosis. A contrast-enhanced abdominal and pelvic computed tomography scan is the recommended diagnostic test and has a sensitivity of 98% to 99% and specificity of 99% to 100%. Approximately 85% of people with acute diverticulitis have uncomplicated diverticulitis (absence of abscess, colon strictures, colon perforation, or fistula formation). Management of patients with uncomplicated diverticulitis consists of observation with pain management (typically acetaminophen) and dietary modification with a clear liquid diet. Antibiotics should be reserved for patients with systemic symptoms such as persistent fever or chills, those with increasing leukocytosis, those older than 80 years, those who are pregnant, those who are immunocompromised (receiving chemotherapy, or high-dose steroids, or have received an organ transplant), and those with chronic medical conditions (such as cirrhosis, chronic kidney disease, heart failure, or poorly controlled diabetes). First-line antibiotics consist of oral amoxicillin/clavulanic acid or cefalexin with metronidazole. For patients who cannot tolerate oral intake, intravenous antibiotic therapy (ie, cefuroxime or ceftriaxone plus metronidazole or ampicillin/sulbactam) is appropriate. Complicated diverticulitis is managed with intravenous antibiotics such as ceftriaxone plus metronidazole or piperacillin-tazobactam and additional invasive management as indicated (ie, percutaneous drainage of associated intra-abdominal abscess or colon resection). Patients with generalized peritonitis should undergo emergent laparotomy with colonic resection. Postoperative mortality for diverticulitis managed electively or emergently is 0.5% for elective colon resection and 10.6% for emergent colon resection. Conclusions and Relevance: In the US, diverticulitis affects approximately 180 per 100 000 people annually. For uncomplicated diverticulitis, first-line therapy is observation and pain control, and antibiotics should be initiated for patients with persistent fevers, increasing leukocytosis, sepsis or septic shock, advanced age, pregnancy, immunocompromise, and certain chronic medical conditions. Treatment of complicated diverticulitis includes intravenous antibiotics, such as ceftriaxone plus metronidazole or piperacillin-tazobactam, and, if indicated, percutaneous drainage of abscess or resection of diseased segment of colon.