What could be causing drainage and blood from the belly button in an adult with no significant past medical history?

Umbilical Drainage and Bleeding in Adults

In an adult with spontaneous umbilical bleeding and drainage, the most likely diagnosis is an umbilical hernia with fat necrosis, which requires urgent CT imaging of the abdomen and pelvis to confirm the diagnosis and guide surgical management. 1

Immediate Assessment

Evaluate hemodynamic stability first by calculating the shock index (heart rate divided by systolic blood pressure). If the shock index is >1, the patient is hemodynamically unstable and requires immediate CT angiography to identify potential intra-abdominal bleeding sources. 2, 3

For hemodynamically stable patients with umbilical discharge:

• Examine the umbilicus for visible skin abnormalities, masses, or hernias 1
• Deep palpation may produce serosanguineous or bloody fluid from the umbilicus 1
• Check for periumbilical pain, abdominal distension, or signs of peritonitis 4

Primary Diagnostic Considerations

Umbilical hernia with fat necrosis is the most common cause of spontaneous umbilical bleeding in adults without prior trauma or surgery. 1 This condition presents with:

• Spontaneous umbilical bleeding or serosanguineous discharge 1
• Periumbilical pain, often with nausea 1
• Mildly elevated inflammatory markers (C-reactive protein) 1
• Fat-containing umbilical hernia visible on CT imaging 1

Other critical differential diagnoses include:

• Persistent embryonal remnants (urachal or omphalomesenteric duct remnants) 1
• Omphalitis (umbilical infection) 1
• Primary or metastatic malignancy to the umbilicus 1
• Endometriosis involving the umbilicus 1

Diagnostic Imaging Algorithm

For hemodynamically stable patients:

• Obtain CT of the abdomen and pelvis with IV contrast as the first-line imaging study 4, 1
• CT will identify umbilical hernias, fat necrosis, embryonal anomalies, masses, or occult intra-abdominal pathology 1
• If CT shows free intraperitoneal fluid or signs of intra-abdominal infection, consider complicated intra-abdominal pathology requiring source control 4

For hemodynamically unstable patients:

• CT angiography (CTA) of the abdomen and pelvis is the first-line investigation 4, 3
• CTA has 79-95% sensitivity and 95-100% specificity for identifying active bleeding 2
• CTA can identify bleeding from visceral vessels, retroperitoneal sources, or intra-abdominal organs without requiring bowel preparation 4

Management Based on Diagnosis

If umbilical hernia with fat necrosis is confirmed:

• Complete surgical resection of the umbilicus is required 1
• This is not amenable to conservative management due to the necrotic tissue 1

If intra-abdominal bleeding is identified:

• For hemodynamically unstable patients with active bleeding on CTA, proceed to angiographic embolization or emergency laparotomy depending on the bleeding source 4
• Maintain hemoglobin >7 g/dL (>4.5 mmol/L) during resuscitation 4
• Avoid fluid overload while maintaining mean arterial pressure >65 mmHg 4

If infection or abscess is identified:

• Percutaneous drainage may be required for source control 4, 5
• Initiate broad-spectrum antibiotics covering gram-negative and anaerobic organisms 4

Critical Pitfalls to Avoid

• Do not assume the bleeding is superficial without imaging evaluation, as occult intra-abdominal pathology may be present 1
• Do not delay CT imaging if the cause is not apparent on physical examination 1
• Do not miss an intra-abdominal source of bleeding that is manifesting through the umbilicus, particularly in patients with hemodynamic instability 4
• Do not attempt conservative management of umbilical hernia with fat necrosis, as surgical resection is required 1