A 25-year-old man came to the emergency department complaining of continuous right para-umbilical pain radiating to the epigastric midline since the previous night. Pain was associated with tenderness. He had no fever and the rest of the physical examination was normal. Laboratory studies showed a normal white blood cell count and C-reactive protein level was 11 mg/L (normal < 10 mg/L). Pain was relieved by paracetamol.