Food protein-induced enterocolitis syndrome (FPIES) is an under-recognized non-IgE-mediated gastrointestinal food allergy. The diagnosis of FPIES is based on clinical history, sequential symptoms and the timing, after excluding other possible causes. It is definitively diagnosed by an oral food challenge test. Unfortunately, the diagnosis of FPIES is frequently delayed because of non-specific symptoms and insufficient definitive diagnostic biomarkers. FPIES is not well recognized by clinicians; the affected infants are often mismanaged as having viral gastroenteritis, food poisoning, sepsis, or a surgical disease. Familiarity with the clinical features of FPIES and awareness of the indexes of suspicion for FPIES are important to diagnose FPIES. Understanding the recently defined clinical terms and types of FPIES is mandatory to suspect and correctly diagnose FPIES. The aim of this review is to provide a case-driven presentation as a guide of how to recognize the clinical features of FPIES to improve diagnosis and management of patients with FPIES.