Inclusion Criteria:
1. Patients aged 18-70 years
2. Diagnosis of uncomplicated AA established by the investigator surgeon that relies on clinico-biological suspicion of acute AA confirm by care radiological tests (US and/or CT and/or MRI) including appendix diameter \>6.0mm. and without:
1. Diffuse peritonitis on clinical exam (i.e., rigid abdomen / four quadrant peritonitis);
2. Radiologic findings of:
i. Free air ii. Walled off fluid collection concerning for an abscess iii. Significant amounts of intra-abdominal fluid throughout abdomen (i.e.,more than trace fluid) iv. Extent of inflammation or adjacent organ involvement on radiologic, appendicular plastron on radiologic imaging
3. Surgery expected within 24 hours after diagnosis
4. Patient able to read and understand the language and content of the study documents and agreeing to adhere to the protocol requirements
5. Patient with internet access at home and a valid email address who declares being able to complete an online questionnaire
6. Signature of the written informed consent form by the patient
7. Affiliation to a French health insurance scheme
Exclusion Criteria:
Exclusion Criteria :
1. Appendicolith visible on radiological tests (US and/or CT and/or MRI)
2. Appendix diameter \>15mm (risk factor of appendicular tumor) visible on radiological tests (US and/or CT and/or MRI)
3. Suspicion of a tumor of the appendix on the imaging exam ((US and/or CT and/or MRI) by the radiologist: (mucocele, pseudomyxoma, neuroendocrine tumor, adenocarcinoma of the appendix, another type of tumor…)
4. Evidence of severe sepsis or septic shock (e.g., new presumed sepsis-related organ dysfunction, elevated lactate, and/or fluid unresponsive hypotension)
5. Severe or uncontrolled comorbidities, such as hepatic cirrhosis, heart failure, acute or chronic kidney failure (estimated glomerular filtration rate \<60mL/min), concurrent hemodialysis or peritoneal dialysis, or treatments using indwelling venous catheters, presence of active cancer or a malignant hemopathy, anticoagulant treatments
6. Recent (within 90 days) placement of surgical implant (e.g., pacemaker, joint prosthesis, mechanical valve) or indwelling Left Ventricular Assist Device
7. Immunodeficiency (e.g., absolute neutrophil count \<500/mm3, chronic immunosuppressive drugs, long term corticosteroids, or known AIDS \[CD4 count \<200/mm3 or AIDS-defining illness assessed by patient history)
8. History of inflammatory bowel disease (Crohn disease, or ulcerative colitis or indeterminate colitis)
9. Ongoing antibiotic therapy for another infection
10. Abdominal/pelvic surgery in the past month
11. Hypersensitivity to Amoxicillin, clavulanic acid and penicillins
12. History of severe immediate hypersensitivity reaction (e.g., anaphylaxis) to another beta-lactam (e.g., a cephalosporin, carbapenem, or monobactam).
13. History of icterus/liver damage related to amoxicillin/clavulanic acid
14. Allergy to any of the excipients listed in section 6.1 of SmPC
15. History of AA treated by antibiotics or appendectomy
16. Pregnant\* or breast-feeding women
17. Participation in another interventional study or being in the exclusion period at the end of a previous study.
18. Mental or cognitive impairment rendering the patient unable to understand study information or to provide informed consent.
19. Patient being a relative of the investigator or of a member of the research team directly involved in the trial (assistant doctors, pharmacists, nurses, or study coordinators).
20. Adult under guardianship or deprived of freedom
