Background: Chilaiditi syndrome (CS) is the interposition of the right colon between the liver and the right hemidiaphragm. The incidence of CS in the general population is very low and it is seen more frequently in adults than in children. Here a case is presented of Chilaiditi syndrome presenting with abdominal pain and vomiting; its initial diagnosis was perforated viscus.
Case Report: A 36-year-old man was admitted to a state hospital with abdominal pain and vomiting which began three days before without any history of prior trauma. On chest x-ray, free air under the right hemidiaphragm was diagnosed as a perforated viscus. Upon physical examination in the authors’ hospital, his abdomen was distended, with normal bowel sounds, but no rebound tenderness were detected on palpation. CS was subsequently confirmed by a chest x-ray and abdominal ultrasound. The patient was managed conservatively and his symptoms resolved over the next 24 hours.
Conclusions: CS may be mistaken for more serious abnormalities, which may lead to unneeded exploratory abdominal surgery. This case emphasizes the importance of considering CS by emergency physicians or surgeons in the differential diagnosis of free air under the right hemidiaphragm on a chest x-ray.

Keywords: Abdominal Pain, chest x-ray, Chilaiditi syndrome, abdominal ultrasound