What are the common causes of bowel obstruction in the jejunum?

Common Causes of Bowel Obstruction in the Jejunum

Adhesions are the most common cause of jejunal obstruction (55-75% of small bowel obstructions), followed by hernias (15-25%), and malignancies (5-10%). 1

Primary Causes of Jejunal Obstruction

1. Adhesions

• Post-surgical adhesions are the leading cause of jejunal obstruction 2, 1
• Can occur even in patients with no prior abdominal surgery (26-100% of cases) 1
• Adhesions can be:
  • Band-type: Single fibrous bands causing compression
  • Matted: Multiple adhesions creating complex obstructions 2

2. Hernias

• Second most common cause of small bowel obstruction 1
• Types affecting the jejunum:
  • External hernias (inguinal, femoral, umbilical)
  • Internal hernias (particularly after bariatric surgery)
  • Incisional hernias from previous surgeries 2

3. Malignancies

• Account for 4-13% of jejunal obstructions 2
• Include:
  • Primary small bowel tumors
  • Metastatic disease
  • Extrinsic compression from adjacent tumors 1

4. Less Common Causes

• Bezoars/foreign bodies: Particularly in patients with altered GI anatomy (e.g., after Roux-en-Y gastric bypass) 3
• Intussusception: Telescoping of one segment of bowel into another 2
• Small bowel volvulus: Twisting of bowel around its mesenteric axis 2
• Meckel's diverticulum: Congenital outpouching of small intestine 2
• Gallstone ileus: Large gallstone migrating into small bowel 2
• Inflammatory bowel disease: Causing strictures 1
• Radiation-induced strictures: Following radiotherapy 1

Clinical Presentation and Diagnosis

Key Clinical Features

• Abdominal distension (highest predictive value)
• Colicky abdominal pain
• Nausea and vomiting (often bilious)
• Absence of flatus or bowel movements
• Visible peristalsis 1

Diagnostic Approach

• CT abdomen and pelvis with IV contrast is the preferred initial imaging modality
  • Diagnostic accuracy >90%
  • Can identify the transition point and potential cause
  • Helps detect complications like strangulation 1, 4

Management Considerations

Surgical Indications

• Complete obstruction
• Signs of strangulation or perforation
• Failure of conservative management 1

Conservative Management

• Appropriate for partial obstruction without signs of complications
• Includes bowel rest, nasogastric decompression, and IV fluids 1

Pitfalls and Caveats

• Delayed diagnosis of strangulation can lead to increased morbidity and mortality
• CT findings may be subtle in early obstruction
• Not all adhesions require surgical intervention - conservative management is successful in many cases
• Beware of closed-loop obstructions, which have higher risk of strangulation 4
• Consider rare causes in patients with unusual presentations or risk factors (e.g., bezoars in patients with previous gastric surgery) 3

Special Considerations

• In patients with no prior abdominal surgery (virgin abdomen), consider other causes beyond adhesions
• Malignancy should be strongly considered in elderly patients with no previous surgery
• The etiology of small bowel obstruction has evolved over time, with adhesions becoming increasingly common as the leading cause 5