What is the treatment for Small Bowel Obstruction (SBO)?

Management of Small Bowel Obstruction (SBO)

Initial non-operative management is the recommended first-line approach for most small bowel obstruction cases without signs of peritonitis, strangulation, or ischemia, with surgical intervention reserved for specific indications. 1, 2

Initial Assessment

• Thorough evaluation should focus on identifying signs requiring emergency surgery: peritonitis, strangulation, or ischemia 1, 3
• Physical examination should include assessment of abdominal distension, abnormal bowel sounds, and examination of all hernial orifices 1
• Laboratory tests should include complete blood count, C-reactive protein, lactate, electrolytes, BUN/creatinine, and coagulation profile 4, 1
• Elevated CRP, leukocytosis with left shift, and elevated lactate may indicate peritonitis or intestinal ischemia requiring urgent surgical intervention 4, 1
• CT scan with intravenous contrast is the preferred imaging technique with superior diagnostic accuracy (>90%) compared to conventional radiography (50-60% sensitivity) 1, 3

Non-Operative Management

• Non-operative management is effective in approximately 70-90% of patients with intestinal obstruction 1, 3

• Key components include:

  • Nil per os (NPO) status 1, 2
  • Nasogastric tube decompression (though its necessity in all patients without active emesis is debated) 2, 5
  • Intravenous fluid resuscitation with crystalloids 1, 2
  • Electrolyte monitoring and correction 1, 2
  • Foley catheter insertion for output monitoring 1
  • Analgesia for pain control 1

• Water-soluble contrast agents (e.g., Gastrografin) serve both diagnostic and therapeutic purposes 1, 2:

  • If contrast reaches the colon within 4-24 hours, this predicts successful non-operative management 1, 2
  • Administration correlates with a significant reduction in the need for surgery 2, 6
  • In patients with SBO in a virgin abdomen (no prior surgery), water-soluble contrast agents improve success rates of non-operative management 4, 2

Indications for Surgical Intervention

• Immediate surgical intervention is required for:

  • Signs of peritonitis 4, 1
  • Suspected strangulation or intestinal ischemia 4, 1
  • Closed-loop obstruction on imaging 1, 3
  • Failure of non-operative management after 72 hours 1, 3
  • Hypotension in the setting of SBO 1

• Surgical approach:

  • Laparotomy has traditionally been the surgical approach of choice for SBO 4, 2
  • Laparoscopy may be considered in selected stable patients, though conversion rates can be high 4, 2
  • Hypotensive patients generally require laparotomy due to better visualization and faster bowel assessment 1

Potential Complications and Pitfalls

• Common complications include:

  • Dehydration with renal injury 1, 3
  • Electrolyte disturbances 1, 3
  • Malnutrition 1, 3
  • Aspiration pneumonia 1, 3
  • Development of pneumonia and respiratory failure is significantly associated with nasogastric tube placement 5

• Avoid delaying surgical intervention in patients with signs of peritonitis, strangulation, or ischemia 1

• Water-soluble contrast agents may further dehydrate patients due to their higher osmolarity, shifting fluids into the bowel lumen 1

• Recurrence of intestinal obstruction is possible after non-operative management (12% within 1 year, increasing to 20% after 5 years) 1, 3

Special Considerations

• For SBO in virgin abdomen (no prior surgery):

  • Adhesions are still a major cause, similar to SBO in general 4
  • CT scan can help establish adhesive etiology by excluding other causes 4
  • Non-operative management success rates range from 17-87% 4
  • Water-soluble contrast agents significantly improve success rates 4, 2

• The use of adhesion barriers can reduce recurrence rates in SBO caused by adhesions, though this is not commonly reported in practice 4, 2

• For malignant bowel obstruction:

  • Surgery after CT scan is the primary treatment option for patients with longer life expectancy 1
  • For patients with advanced disease or poor condition, medical management may include pharmacologic measures, parenteral fluids, endoscopic management, and enteral tube drainage 1, 3