During intrauterine development the primordia of the developing gastrointestinal and urinary tract come into close proximity in the umbilicus where the communication of these structures with the external environment is usually obliterated. In a small percentage of patients the omphalomesenteric duct and/or urachus may remain completely or partially patent. When complete patency is present, drainage of mucus, stool, or urine may occur. Partial patency may be manifest by an abdominal mass or by no symptoms at all. Definitive treatment includes total excision of the omphalomesenteric duct and/or urachus, lest recanalization of remnant tissue or carcinoma in later life occur.