A 10 year old male presents to the ER with abdominal pain. H…

A 10 year old male presents to the ER with abdominal pain. His father reports this has been going on for 2 days and he has had nausea and vomiting for 1 day. Your physical exam is significant for focal right lower quadrant tenderness over McBurney’s point and a positive psoas sign. Which of the following is the MOST likely diagnosis?