What is the initial treatment for bowel obstruction?

Initial Management of Bowel Obstruction

The initial treatment for bowel obstruction should include NPO (nothing by mouth), nasogastric tube decompression, IV fluid resuscitation with crystalloids, and electrolyte monitoring and correction. 1

Diagnosis and Assessment

• Bowel obstruction accounts for approximately 15% of hospital admissions for acute abdominal pain and 20% of cases requiring acute surgical care 2
• Initial evaluation should focus on identifying signs of peritonitis, strangulation, or ischemia, which would require emergency surgery 1
• Physical examination should include assessment of abdominal distension (present in 65.3% of cases), abnormal bowel sounds, and examination of all hernial orifices 1, 3
• Laboratory tests should include complete blood count, C-reactive protein, lactate, electrolytes, BUN/creatinine, and coagulation profile 1
• Elevated C-reactive protein, leukocytosis with left shift, and elevated lactate may indicate peritonitis or intestinal ischemia 1

Imaging

• CT scan with intravenous contrast is the preferred imaging technique with superior diagnostic accuracy compared to conventional radiography and ultrasound 2, 1
• CT can identify the location, degree, and potential causes of obstruction 1
• Abdominal plain X-ray is often the first radiologic study performed but has limited diagnostic value (50-60% sensitivity) 2
• Water-soluble contrast administration enhances diagnostic value and can predict the need for surgery 2, 1
• If contrast has not reached the colon on an abdominal X-ray 24 hours after administration, this indicates a high likelihood of non-operative management failure 2

Non-Surgical Management

• Non-surgical management is effective in approximately 70-90% of patients with intestinal obstruction due to adhesions 1

• Key components include:

  • NPO (nothing by mouth) 1
  • Decompression with nasogastric tube or long intestinal tube 1
  • Fluid resuscitation with crystalloids 1
  • Monitoring and correction of electrolytes 1
  • Water-soluble contrast administration (which correlates with a significant reduction in the need for surgery) 1

• Long intestinal tubes may be more effective than nasogastric tubes but require endoscopic insertion 1

Indications for Surgical Intervention

• Immediate surgical intervention is required for:

  • Signs of peritonitis 1
  • Strangulation 1
  • Intestinal ischemia 1
  • Closed-loop obstruction on imaging 1
  • Failure of non-surgical management after 72 hours 1

• Hernias carry a significantly higher risk of strangulation compared to other causes of obstruction 3

• Bowel ischemia occurs in approximately 14% of cases, necrosis in 9.3%, and perforation in 5.3% of bowel obstruction cases 3

Cause-Specific Management

• For adhesive small bowel obstruction:

  • Conservative management with decompression and fluid resuscitation is appropriate initially 1
  • Surgery is indicated if no improvement after 72 hours 1, 4

• For malignant bowel obstruction:

  • Surgery after CT scan is the primary treatment option for patients with longer life expectancy 2
  • For patients with advanced disease or poor condition, medical management may include:
    • Pharmacologic measures (opioids, antiemetics, corticosteroids) 2
    • Parenteral fluids 2
    • Endoscopic management 2
    • Enteral tube drainage 2
    • Somatostatin analogs (octreotide) and/or anticholinergics when gut function is no longer possible 2

• For sigmoid volvulus without ischemia:

  • Endoscopic detorsion followed by same-admission sigmoid colectomy with primary anastomosis 2
  • Exclusively endoscopic therapy without surgery should be reserved for high-surgical-risk patients 2

• For obstructing left colon cancer:

  • Self-expanding metallic stents may be preferred to colostomy as they are associated with similar mortality/morbidity rates but shorter hospital stay 2, 1

Complications and Pitfalls

• Common complications include dehydration with renal injury, electrolyte disturbances, malnutrition, and aspiration 1
• Antiemetics that increase gastrointestinal motility (such as metoclopramide) should not be used in patients with complete obstruction but may be beneficial in partial obstruction 2
• Recurrence of intestinal obstruction due to adhesions is possible after non-surgical management (12% within 1 year, increasing to 20% after 5 years) 1
• Water-soluble contrast agents may further dehydrate patients due to their higher osmolarity, shifting fluids into the bowel lumen; this is particularly dangerous in children and elderly adults 2