PANRE-LA

Diverticulosis is one of the most common causes of painless hematochezia in older adults. Approximately 4% of individuals with diverticulosis will go on to develop diverticulitis, an inflammation of the colonic wall that classically presents with left lower quadrant abdominal pain. The majority of diverticulitis involves the sigmoid colon, mimicking the symptoms of appendicitis but on the left side of the abdomen. Diverticulitis is diagnosed by CT scan, preferably with oral and IV contrast, which will show bowel wall thickening. Importantly, colon cancer may have similar findings on CT scan, making diverticulitis difficult to distinguish from colon cancer. CT scan will also reveal the presence of complications such as abscess formation, fistulization, or perforation. Patients with uncomplicated acute diverticulitis may be discharged home on oral antibiotics with coverage for gastrointestinal gram-negative rods and anaerobes. Ciprofloxacin and metronidazole or trimethoprim-sulfamethoxazole and metronidazole are two commonly used regimens. These patients should be given clear return precautions for worsening fever or abdominal pain, as this could indicate treatment failure or the development of complications.

Complicated diverticulitis is indicated by the presence of abscess formation, obstruction, fistulization or perforation. All complicated diverticulitis should be admitted for inpatient intravenous antibiotic treatment (A) and possible surgical intervention. Uncomplicated diverticulitis with the presence of high fever, significant leukocytosis, severe abdominal pain, or inability to tolerate oral intake should also prompt inpatient treatment. Elective colon resection (C) is an option for patients with recurrent diverticulitis or those with high risk of complications from recurrent diverticulitis, such as those with a complicated first episode or with immunosuppression. However, this patient does not have an indication for elective colon resection. Colonoscopy (D) to assess the extent of diverticular disease and exclude colon cancer is indicated in all patients with diverticulitis who have not had a colonoscopy in the last year. This should occur after complete resolution of the diverticulitis. Colonoscopy is not indicated in acute diverticulitis, and colonoscopy before resolution of the diverticulitis increases the risk of bowel perforation and serious complications.