In medicine, a dolichocolon (word derived from ancient Greek "dolichos", the long distance in running, and colon) is an abnormally long large intestine. It should not be confused with an abnormally wide large intestine, which is called a megacolon.

Dolichocolon may predispose to abnormal rotation (see volvulus) and interposition between the diaphragm and the liver (see Chilaiditi syndrome). It is more commonly seen in the elderly, some psychiatric patients or in institutionalised individuals. It is not, however, a part of normal aging. The exact cause remains unknown.

Dolichocolon is often an incidental finding on abdominal X-rays or colonoscopy. It is not by itself a disease and as such requires no treatment.

The occurrence (incidence) on abdominal or chest X-rays is around 0.1% but it can be up to 1% in series of older adults. It has also been reported in children.

Chilaiditi syndrome is a rare condition when pain occurs due to transposition of a loop of large intestine (usually transverse colon) in between the diaphragm and the liver, visible on plain abdominal X-ray or chest X-ray.

Normally this causes no symptoms, and this is called Chilaiditi's sign. The sign can be permanently present, or sporadically. This anatomical variant is sometimes mistaken for the more serious condition of having air under the diaphragm (pneumoperitoneum) which is usually an indication of bowel perforation, possibly leading to surgical interventions.

Chilaiditi syndrome refers only to complications in the presence of Chilaiditi's sign. These include abdominal pain, torsion of the bowel (transverse colon volvulus) or shortness of breath.