A less invasive approach to the treatment of left-sided colonic diverticulitis has emerged in the last decade. The standard of care for perforated or complicated diverticulitis evolved from a Hartmann’s procedure, to resection and primary anastomosis, to treatment with antibiotics and percutaneous drainage in a carefully selected (Hinchey grade 2) patient subset. Recently, laparoscopic lavage emerged as a promising less invasive treatment for selected cases of Hinchey 3 patients. Likewise, for nonperforated or uncomplicated diverticulitis the approach is becoming less aggressive with a change from intravenous antimicrobial therapy, starvation and admission, to oral antibiotics and finally to observation and outpatient treatment. This less invasive or aggressive approach is due to expanding evidence on optimal treatment and is congruent with an increasing understanding that diverticulitis comprises different disease entities with heterogeneity between patients. The disease should be targeted by specific approaches, after a meticulous assessment of the diverticulitis stage, and tailored to an individual basis. Avoidance of overtreatment has obvious benefits: less in-hospital treatment, cost reduction, diminished development of antimicrobial resistance, reduction in complication rate and side effects and presumably a better quality of life for the patient. In conclusion, one might say we have overtreated the majority of diverticulitis patients for decades. More research is needed to explain the pathogenesis and multifactorial etiology and in the near future hopefully several unanswered questions regarding the optimal management of patients with different stages of diverticulitis will be answered by various ongoing trials.