Primary intestinal obstruction complicated by persistent descending mesocolon

Persistent descending mesocolon is an uncommon developmental anomaly which results from failure of fusion of the descending mesocolon with the posteri or parietal peritoneum. It is asymptomatic in most cases and rarely causes intestinal obstruction. We report here a case of primary intestinal obstruc tion complicated by a persistent descending mesocolon. A 66-year-old man wi thout prior laparotomy was admitted with a diagnosis of small bowel obstruc tion. Pre-operative investigation demonstrated a segmental jejunal stenosis and a persistent descending mesocolon as possible causes of the obstructio n. Laparotomy showed that the cause of the obstruction was the jejunal sten osis, not the persistent descending mesocolon. The stenosis was resected, b ut correction of the anomaly was not performed. The patient made an unevent ful recovery after the operation. From our limited experience, persistent d escending mesocolon need not be surgically corrected when it is not conside red to be the cause of obstruction and another definite cause co-exists.