What are the possible causes of drainage in a belly button, considering various patient factors such as medical history and demographics?

Causes of Belly Button Drainage

Belly button drainage most commonly results from infection of the umbilical area, but in patients with feeding tubes (G-tubes/PEG tubes) placed through or near the umbilicus, mechanical causes including excessive tube tension, side torsion, and peristomal infection are the primary culprits.

Primary Causes in Patients WITHOUT Feeding Tubes

Infectious/Inflammatory Causes

• Omphalitis (umbilical infection) presents with purulent drainage, erythema, warmth, and tenderness around the belly button, requiring antibiotic coverage for skin flora including Staphylococcus and Streptococcus species 1
• Fungal infection occurs with chronic moisture accumulation in the umbilical fold, particularly in obese patients or those with poor hygiene, presenting with malodorous white or yellow discharge 1
• Pilonidal sinus or urachal remnant infection can present with intermittent drainage from the umbilicus, often requiring imaging to identify the tract 1

Anatomic/Congenital Causes

• Patent urachus (connection between bladder and umbilicus) causes clear or urine-like drainage, more common in infants but can present in adults 1
• Umbilical hernia with incarceration may present with drainage if there is tissue necrosis or abscess formation requiring urgent surgical evaluation 1
• Omphalomesenteric duct remnant can cause feculent or mucoid drainage if a connection persists between the small bowel and umbilicus 1

Primary Causes in Patients WITH G-Tubes/PEG Tubes

Mechanical Causes (Most Common)

• Excessive compression between internal and external fixation devices is the leading cause of peristomal leakage, creating tissue necrosis and tract enlargement 2
• Side torsion of the tube leads to ulceration and progressive enlargement of the stoma tract, creating pathways for gastric content leakage 2
• Balloon deflation or incorrect volume in balloon-type tubes allows migration and leakage; manufacturer specifications should be verified weekly 2
• Incorrect tube length (particularly with button gastrostomy devices) creates a poor seal at the stoma site 2

Buried Bumper Syndrome

• Partial or complete gastric mucosal overgrowth over the internal bolster occurs in 0.3-2.4% of patients, presenting with peristomal leakage, immobile tube, and resistance with feeding 2
• Risk factors include excessive bolster tension, malnutrition, and significant weight gain from successful enteral nutrition 2

Infectious/Inflammatory Causes

• Peristomal infection occurs in up to 30% of G-tube cases, causing local tissue breakdown with purulent drainage 2
• Excessive granulation tissue results from excess moisture, friction from poorly secured tubes, or critical colonization, appearing as friable red tissue that bleeds easily 1, 2
• Fungal skin infection creates a vicious cycle with chronic moisture and leakage 2

Increased Gastric Output

• Increased gastric acid secretion directly contributes to leakage and surrounding skin breakdown 2
• Gastroparesis causes gastric stasis with increased residuals that overflow around the tube 2
• Increased intra-abdominal pressure from constipation, ascites, or other causes forces gastric contents around the tube 2

Diagnostic Approach

Initial Assessment

• Examine the umbilical area for erythema, induration, fluctuance, and character of drainage (purulent, serous, bloody, feculent, or gastric content) 1, 2
• In patients with G-tubes, check bolster tension first, verify balloon volume, assess for side torsion, and examine for infection 2
• Obtain cultures of purulent drainage for bacterial and fungal organisms to guide antibiotic therapy 1

Imaging When Indicated

• Ultrasound is first-line for evaluating fluid collections, abscesses, or anatomic abnormalities in the umbilical region 1, 3
• CT abdomen/pelvis with IV contrast is indicated when ultrasound is equivocal, when deeper pathology is suspected, or to evaluate for intra-abdominal abscess or fistula 1
• Contrast studies may be needed to identify patent urachus, omphalomesenteric duct remnants, or enteric fistulas 1

Management Algorithm

For Non-Tube Related Drainage

• Clean the umbilical area twice daily with soap and water, ensuring thorough drying to prevent moisture accumulation 1
• Start empiric antibiotics covering skin flora (cephalexin or dicloxacillin) for suspected bacterial infection 1
• Apply topical antifungal agents (clotrimazole or miconazole) for fungal infections 1
• Refer for surgical evaluation if anatomic abnormalities (patent urachus, omphalomesenteric duct) are identified 1

For G-Tube Related Drainage

• Immediately adjust bolster tension to ensure proper positioning without excessive compression 2
• Apply zinc oxide-based barrier products to all exposed skin to prevent acid-induced breakdown 2
• Use foam dressings instead of gauze to lift drainage away from skin and reduce maceration 1, 2
• Start proton pump inhibitors to decrease gastric acid secretion and minimize leakage volume 2
• Address constipation to reduce intra-abdominal pressure and consider prokinetic agents if gastroparesis is contributing 2
• If all measures fail, remove the tube for 24-48 hours to permit slight spontaneous closure of the tract, then replace with a tube that fits more closely 1

Critical Pitfalls to Avoid

• Never ignore difficulty mobilizing a G-tube, as this is an alarming signal for buried bumper syndrome requiring immediate endoscopic evaluation 2
• Do not use hydrogen peroxide after the first week of G-tube placement, as it irritates skin and contributes to stomal leaks 2
• Avoid upsizing the G-tube as a solution to leakage, as this typically worsens the problem by further enlarging the tract 2
• Do not dismiss small amounts of drainage as insignificant without proper follow-up, as this doesn't exclude early or slowly developing pathology 3
• Never remove drains prematurely in post-surgical patients, as the drain must remain until output decreases significantly or definitive management is undertaken 4