Inclusion Criteria:  -Children aged 24-59 months with suspected Shigella infection (clinical features of fever, mucus and/or blood in stools, tenesmus, and RBC and leucocytes >10 per hpf)  Exclusion Criteria:  Child received another antibiotic prior to presentation (as confirmed by bottle or prescription) Severe acute malnutrition (SAM), defined as weight-for-height z-score less than -3 or mid upper arm circumference less than 115mm Patients with other infectious foci who are potentially unresponsive to treatment with orally administered medication Patients in whom the efficacy and safety of the study drug is difficult to determine because of a progressive, complicated, or severe underlying disease believed to critically influence the onset of the infection, its clinical course, and therapeutic efficacy Patients with convulsive disorders, such as epilepsy, as an underlying disease Patients with a known lipid metabolism disorder or congenital carnitine deficiency Patients with severe hepatic or renal dysfunction Patients with a history of allergy to β-lactam antibiotics (e.g., carbapenems, penicillin, and cephems) Patients who have received other antibiotics for the illness and exhibited improvements Clinically improved after first-line therapy Unable to provide a stool sample at enrolment