IMPORTANCE: Diverticulitis of the sigmoid colon is an increasingly common disease. Patterns of care and management guidelines have significantly evolved in recent years. OBJECTIVES: To review and classify the primary data published since 2000 that are guiding decision making, technical considerations, and the outcomes of surgery for sigmoid diverticulitis. EVIDENCE REVIEW: We searched the National Guideline Clearinghouse, PubMed, and Cochrane databases for studies pertaining to the diagnosis and management of chronic and recurrent diverticulitis from January 1, 2000, to March 31, 2013. We supplemented this automated search with references drawn from included studies and PubMed.We rated the level of evidence according to American College of Cardiology/American Heart Association guidelines. FINDINGS: We identified 68 studies meeting inclusion criteria for final review. The studies were almost exclusively observational and had limited certainty of treatment effect.We found that complicated recurrence after recovery from an uncomplicated episode of diverticulitis is rare (<5%) and that age at onset younger than 50 years and 2 or more recurrences do not increase the risk of complications. Chronic symptoms may persist even after resection in 5%to 22%of patients. Prophylactic surgery is generally not recommended for average-risk patients with diverticulitis, irrespective of the number of episodes of acute, noncomplicated disease. Decisions to proceed with colon resection should be based instead on the patient-reported frequency and severity of diverticulitis symptoms. CONCLUSIONS AND RELEVANCE: The prior standard for proceeding with elective colectomy following 2 episodes of diverticulitis is no longer accepted. Decisions to proceed with colectomy should be made based on consideration of the risks of recurrent diverticulitis, the morbidity of surgery, ongoing symptoms, the complexity of disease, and operative risk. Laparoscopic surgery is preferred to open approaches. Recent evidence suggests that existing guidelines should be updated. Copyright 2014 American Medical Association. All rights reserved.