This is a feasibility study that will be performed at the Astrid Lindgren Children´s Hospital, Karolinska University Hospital, Stockholm, Sweden. It will involve 50 patients, randomized to either conservative, non-operative, treatment with antibiotics OR surgery. The study will test an computerized randomization system, the availability of patients willing to participate in the trial and the trial protocol. The investigators will assess the characteristics of the patients who agree to participate in the study and those who do not. The investigators will explore short term outcome and design suitable long term outcome measures.