Appendicitis is the most common cause for emergency surgery and intra-abdominal sepsis in healthy children worldwide. Incidence is high in childhood and disease morbidity arises from pathologic and iatrogenic injuries to the peritoneum: perforation of a diseased appendix results in severe peritoneal infection and inflammation while laparoscopic surgery to remove appendiceal tissue exposes the delicate and vulnerable peritoneum to hostile and desiccating conditions of a pneumoperitoneum. The proposed research project begins by evaluating associations between severity of peritoneal damage and subsequent clinical outcomes of New Zealand children affected by appendicitis. This is followed by systematic reviews critically appraising and summarising evidence for and against contemporary and controversial practices that target peritoneal inflammation and injury in paediatric appendicitis. Lastly, two hypothesis-driven randomised controlled clinical trials test effectiveness of surgical management strategies aimed at reducing peritoneal dysfunction in order to improve disease, social and economic outcomes of paediatric appendicitis in New Zealand.