An umbilical fistula is a term that describes a connection between organs and the external environment through the umbilicus, but vascular fistulas may also arise at this anatomical site. Various forms of intestinal and urinary fistulas are described in the literature, and extensive imaging studies are required to confirm the exact type.
Earlier reports considered umbilical fistulas to be rare and were primarily diagnosed as complications of abdominal surgery , but numerous congenital or secondary conditions have subsequently shown to be involved in their pathogenesis. The clinical presentation of an umbilical fistula significantly depends on its type     :
Umbilical discharge or presence of an abdominal mass mandates a thorough physical examination and the use of various imaging studies to confirm the etiology. A detailed inspection and palpation of the abdomen may provide important clues, but ultrasonography is considered to be the first diagnostic method used in such circumstances, especially when urachal diseases and vascular fistulas are present   . If the diagnosis remains inconclusive, computed tomography (CT), magnetic resonance imaging (MRI), voiding cystourethrography (when urinary discharge from the umbilicus is reported) and a fistulogram are recommended, with CT carrying the highest rate of detection . Although rare, diagnostic modalities may fail to confirm the underlying cause, which is why some patients receive a diagnosis after surgery . Apart from imaging studies, the value of laboratory workup should be pointed out, especially in patients who suffer from hemorrhage in arteriovenous fistulas. For this reason, a complete blood count (CBC), a full coagulation panel and renal function tests should be obtained.