Colonic diverticulitis is a painful gastrointestinal disease that recurs unpredictably and can lead to chronic gastrointestinal symptoms. Gastroenterologists commonly care for these patients. The purpose of this clinical practice update is to provide practical and evidence-based advice for diverticulitis management. We reviewed systematic reviews, meta-analyses, randomized controlled trials, and observational studies to develop 14 best practices. In brief, computed tomography is often necessary to make a diagnosis.