Absence of transverse colon, persistent descending mesocolon, displaced small and large bowels: a rare congenital anomaly with a high risk of volvulus formation.

Congenital anomalies such as positional anomalies of the right half of the colon are more common when compared to its left half. We report a rare case of congenital anomaly where the transverse colon was totally absent. Ascending colon continued as descending colon at the right colic flexure. Ascending and descending colons formed an inverted U shaped loop which was situated in the right half of the abdomen. The sigmoid colon began from the descending colon, on the right side of the midline and coursed to the left iliac fossa. The terminal part of ascending colon and entire descending colon had a persistent mesocolon. The jejunum and ileum were situated in the upper left part of the abdominal cavity. This anomaly can cause volvulus of the colon at any stage of life. Furthermore, the knowledge of this anomaly is very useful for radiologists, gastroenterologists and surgeons.