Sub investigator is working no longer in the hospital. No participants were enrolled.

The purpose of this study is to evaluate the frequency of positive free fluid cultures in both perforated and non-perforated appendicitis. In addition predictors of positive free fluid cultures will be analyzed.

Prior to surgery, all patients will receive antibioprophylaxis. In case of free peritoneal fluid, a sample is aspirated and sent for microbiology. A lavage with saline is not necessary. The decision to start postoperative antibiotic is left at the discretion of the surgeon. The decision to leave an abdominal drain is left at the discretion of the surgeon.

The use of a preoperative single dose administration of antibiotics has been extensively studied and found beneficial in the prevention of SSI in appendicitis. However, the use of continued postoperative antibiotics has barely been studied. The sparse evidence that exist does not seem to support its systematic use. During appendectomy the surgeon frequently encounters turbid free fluid, even in non-perforated appendicitis. It is common practice in Belgium to continue antibiotic prophylaxis for 5 days after aspiration and lavage. Although the aspect often seems purulent, it is unknown in what percentage this fluid is contaminated. Also, it is unknown whether after aspiration and lavage intra-abdominal drains are necessary.

Inclusion Criteria:

• Appendicitis (Perforated/ Non-perforated) Free fluid Age: 6 - 90y

Exclusion Criteria:

• Immunosuppression (recent chemotherapy, chronic use of immunosuppressive medication) Age < 6 and > 90y

Patients with perforated or non-perforated appendicitis