Omphalomesenteric Duct Fistula with Ileal Prolapse within an Omphalocele

Omphalomesenteric duct (OMD) anomalies are common congenital gastrointestinal abnormalities, occurring in approximately 2 per cent of the population.1 They range from the more commonly described Meckel's diverticulum to a completely patent OMD fistula with the bowel.1 Simultaneous presentation of an OMD fistula with ileal prolapse through an omphalocele at birth is very rare. Because the bowel completes its rotation as it reenters the abdomen, omphalocele is invariably a disorder of rotation. Normally, this duct involutes, but in an estimated 2 to 3 per cent of the population, a portion or entirety of the duct remains patent.2 Persistence of the OMD at the enteric end with no connection to the umbilicus describes the wellknown Meckel's diverticulum.3 Persistent patency at the umbilicus without connection to the bowel results in a sinus tract which may present with signs of drainage and infection.1 An OMD cyst may occur when only the central portion between the umbilicus and ileum remains patent.