What is the management and treatment of large bowel obstruction?

Management and Treatment of Large Bowel Obstruction

CT scan with IV contrast is the gold standard for diagnosing large bowel obstruction, followed by prompt intervention within 72 hours if conservative management fails or immediately if signs of peritonitis, ischemia, or strangulation are present. 1

Diagnostic Approach

1. Initial Assessment:

   • Laboratory tests: Complete blood count, lactate, electrolytes, CRP, BUN/creatinine
   • Warning signs of peritonitis: CRP >75, leukocytes >10,000/mm³ (though these have low sensitivity) 1

2. Imaging:

   • CT scan with IV contrast is the preferred diagnostic modality 1
   • Water-soluble rectal contrast can be administered when diagnosis remains uncertain 2
   • For pregnant women and children, MRI is a valid alternative (sensitivity 95%, specificity 100%) 2

3. Colonoscopy:

   • Limited role in diagnosis of large bowel obstruction
   • Can exclude other causes and allow for biopsy in suspected malignancy
   • CO₂ insufflation preferred over air to reduce risk of bowel ischemia 2

Conservative Management

Conservative management is appropriate for:

• Partial obstructions without signs of peritonitis/ischemia
• Diverticular obstruction (which often resolves with conservative treatment) 2

Conservative approach includes:

• Nil per os (NPO)
• Fluid and electrolyte replacement
• Bowel decompression via nasogastric tube
• Water-soluble contrast administration (both diagnostic and therapeutic) 1

A 72-hour period is considered safe and appropriate for conservative treatment, with possible extension if clinical improvement is observed without deterioration 1.

Surgical Management

Indications for Immediate Surgery:

• Signs of peritonitis
• Suspected bowel ischemia or strangulation
• Failed conservative management after 72 hours 1

Surgical Options:

1. Laparotomy:

   • Traditional approach for unstable patients
   • Higher success rate but also higher morbidity (30-day morbidity of 39%) 1

2. Laparoscopic approach:

   • Suitable for hemodynamically stable patients with simple cases
   • Completion rate of 35% with 60% conversion rate to open laparotomy 1

3. Colonic Stenting:

   • Self-expanding metal stents (SEMS) can be an option for malignant obstruction
   • Should be considered after multidisciplinary review 1

Specific Etiologies and Their Management

Malignant Obstruction (>60% of cases) 3

• Options include emergency resection, staged resection, or stenting as bridge to surgery
• Decision based on patient condition, tumor location, and available expertise

Volvulus

• Sigmoid volvulus often requires prompt decompression via sigmoidoscopy
• Recurrent or non-reducible cases require surgical intervention 2

Diverticular Disease

• Often resolves with conservative management
• Surgery indicated if conservative management fails 2

Adhesive Obstruction

• Less common in large bowel than small bowel
• May require adhesiolysis if conservative management fails 1

Post-Treatment Care

• Early mobilization
• Progressive diet advancement when appropriate
• Monitoring for signs of recurrent obstruction
• Close follow-up to identify underlying causes 1

Potential Pitfalls and Complications

• Delaying surgical consultation when signs of strangulation are present
• Failure to recognize complete versus partial obstruction
• Inadequate fluid resuscitation
• Overlooking the possibility of closed-loop obstruction 1
• Opioid use can mask symptoms and invalidate tests of bowel motility 1

Special Populations

• Pregnant women: High failure rate (94%) of non-operative treatment with 17% risk of fetal loss 1
• Diabetic patients: May require earlier intervention due to higher risk of complications 1
• Elderly patients: Consider frailty index and quality of life in management decisions 1

Outcomes

• Prompt intervention (within 2 days) results in decreased length of stay and greater likelihood of discharge to home 4
• Recurrence rate after surgical management is approximately 8% at 1 year 1
• Morbidity rates range from 10-39% 1

Remember that large bowel obstruction is a potentially life-threatening condition requiring prompt assessment and treatment to reduce the associated high morbidity and mortality rates 3.