In the early stage of intestinal development most of the abdominal cavity is occupied by the massive liver and large mesonephric kidneys. Hence, there is 'not enough space to accommodate the fast-growing midgut. Consequently, the primary intestinal loop is forced to herniate into the ex-traembryonic coelom present in the umbilical cord. This temporary migration of the intestines into the proximal part of the umbilical cord constitutes physiological umbilical hernia. Normally, the intestines stay within the umbilical cord from the 6th to 10th week of development.