Umbilicus and its extensive clinical repertoire.

The umbilicus is involved in a wide range of abnormalities in infants and children. The most severe are evident at birth and include exomphalos (omphalocele) and gastroschisis, both of which can be life-threatening but are easy to diagnose. Exomphalos is often associated with other congenital abnormalities, whereas the associated problems in gastroschisis are largely confined to the gut. Infection of the umbilicus in the neonate presents as omphalitis. The causes of a moist umbilicus following separation of the umbilical stump are multiple, from the relatively minor umbilical granuloma or ectopic bowel mucosa to the more significant patent urachus that leaks urine. Patency of the entire vitello-intestinal (omphalomesenteric) tract allows air and faecal fluid to drain through the umbilicus. The clinical manifestations of persistence of the vitello-intestinal tract vary markedly according to which part remains: clinical presentations include melaena and anaemia, closed-loop bowel obstruction and Meckel diverticulitis. An umbilical hernia occurs when the umbilical cicatrix fails to close. On the other hand, the umbilicus has its uses, which range from being a route for intravenous access in the neonate to being a convenient point of access in laparoscopic surgery.