A stark contrast exists between the physiologic importance of the umbilicus during development and after birth. During development, the umbilical cord functions as a channel allowing blood flow between the placenta and fetus; it also serves an important role in the development of the intestine and the urinary system. After birth, once the umbilical cord falls off, no evidence of these connections should be present, except the umbilical scar, as landmark of the previously exist cord. Nevertheless, umbilical disorders are frequently encountered in paediatric surgery. It has been estimated that 30% of births have some type of umbilical cord finding. These disorders range from the very common umbilical hernia to infections such as omphalitis, which can be life-threatening, and from simple straightforward anatomy like granuloma to complicated and sophisticated malformations, like vitellointestinal and urachal anomalies. Most patients with umbilical problems present with a mass or drainage from the umbilicus. An understanding of the anatomy and embryology of the abdominal wall and umbilicus is important to identify and properly treat common as well as rare complicated conditions.
In 1916, W. B. Saunders Company, Philadelphia and London, published the first book concerned with umbilical embryology, anatomy and disorders, which was written by the Johns Hopkins University gynaecologist Thomas Stephen Cullen; since then umbilical disorders attract many scientists to publish countless case reports, case series and few original researches.
The navel clinically known as the umbilicus, colloquially known as the belly button or tummy button, is a hollowed or sometimes raised area on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel. The umbilicus is used to visually separate the abdomen into quadrants.
The umbilicus itself has been described as a round dermal projection or depressed scar on the centre of anterior abdominal wall surrounded by a natural skin fold that measures 1.5–2 cm in diameter and lies anatomically within the midline at the level of the superior iliac crests .