Intestinal obstruction in a case of duplication of the terminal ileum.

Duplication of the alimentary tract is a rare but well-known condition, the aetiology of which is imperfectly understood. The present knowledge and theories are discussed by Willis (1958). Duplications occur on the dorsal or mesenteric aspect of the normal alimentary tract and may or may not communicate with it. Often they do not communicate and the secretions of the epithelial lining lead to cyst formation, giving rise to a variety of symptoms. Such cysts are found throughout the alimentary tract but are most common in the terminal ileum. They are lined by epithelium, which resembles the adjacent bowel but which may contain any type of intestinal epithelial cell. The muscular coat is intermingled with that of the adjacent bowel and their blood supply is common, making operative dissection of the cyst impossible (Gross, 1953). Intestinal obstruction may result from pressure on the adjacent bowel when it and the cyst lie where movement is restricted. Duodenal duplications are particularly prone to give rise to obstruction in infancy, showing a picture akin to that seen in pyloric stenosis. Duplications in the rest of the bowel are not likely to give rise to early obstruction as the bowel can be displaced by the growing cyst. A case is described in which an anatomical structure was seen to be the cause of the neonatal intestinal obstruction.