Identification of the Optimal Treatment Strategy for Complex Appendicitis in the Pediatric Population

Inclusion Criteria: Eligible for inclusion are all children \<18 years old that need to undergo treatment for the suspicion of complex appendicitis. Suspicion of complex appendicitis is based upon the following predefined criteria: 4 or more points on our scoring system developed to predict complex appendicitis. The diagnostic accuracy of this scoring system is 91% (Range: 84-98%). This scoring system consists of five variables (clinical, biochemical and radiological,each awarded points). In case the total score is 4 or more points, the patient is likely to have complex appendicitis. Variables included in the scoring system are: * Diffuse abdominal guarding (3 points) * CRP level more than 38 mg/L (2 points) * Signs on ultrasound / imaging indicative for complex appendicitis (2 points) * More than one day abdominal pain (2 points) * Temperature more than 37.5 degrees Celsius (1 point) Or High index of suspicion of complex appendicitis by the treating physician. If this is the case, the treating physician will make pre-treatment note upon what clinical, biochemical or radiological variable the high index of suspicion is based. Exclusion Criteria: * Adult patients (=18 years old) * Children with a suspicion of simple appendicitis (based upon the previous mentioned scoring system and radiological features)