interposed colon

Interposition of the colon refers to the colon (most commonly the hepatic flexure) entering the space between the liver and diaphragm through the anterior or posterior hepatic space. It may be asymptomatic, or may cause dull pain in the right hypochondrium, abdominal distension, and even gastrointestinal obstruction. The symptoms thus caused are called interposition of the colon syndrome, also known as Chilaiditi syndrome, in which the right colic flexure becomes interposed between the liver and the diaphragm. The cause is not in the intestinal tract itself; ptosis of the liver and abnormal position form the basis of this condition. It is often due to developmental abnormalities such as excessively long, weak, or absent hepatic ligaments, which cause the liver to descend and the space between it and the diaphragm to widen, allowing the colon to become interposed. Congenital weakness of the diaphragm or diaphragmatic paralysis are predisposing factors. In addition, in some patients with liver cirrhosis, marked atrophy of the right hepatic lobe enlarges the hepatodiaphragmatic space, and this condition may also be seen.