Diverticulitis refers to the inflammation or infection of diverticula along the large bowel wall. It represents the severe end of the diverticular disease spectrum, which becomes more common with advancing age. Diverticular disease is classified into asymptomatic diverticulosis, uncomplicated diverticulitis, and complicated diverticulitis. Key red flags to identify during consultation include signs of peritonism due to perforated diverticula, lower gastrointestinal bleeding, and poor response to initial conservative treatment. Initial investigations should aim to detect inflammation, infection, or complications, followed by confirmatory tests as resources permit. Classification is ideally based on the modified Hinchey Classification and the Diverticulitis Category, particularly if abdominal computed tomography (CT) is available. Non-pharmacological measures alone may suffice in mild, uncomplicated cases, whereas antibiotics are indicated for patients with worsening symptoms. Close follow-up is essential to monitor for red flags, recurrence of symptoms, and to identify those who require referral or inpatient care.