Physicians who wait for clear, easily recognizable signs will miss many diagnoses. The Gastroenteritis is one of the most common medical emergencies in emergency department (ED). The Appendicitis continues to be the most common acute surgical emergency. The diagnosis of early appendicitis continues to be a challenge for the emergency physician. There is a differential diagnosis between gastroenteritis and appendicitis. The presentation of loose motion or diarrhea cannot be rule out appendicitis alone its need a global of clinical assessment, investigation and imaging (1). In this case we will discuss a case which presented as gastroenteritis, then diagnosed by CT scan as appendicitis but the surgeon and histopathological report diagnosed it back Gastroenteritis.