What is the management and treatment of large bowel obstruction?

Management and Treatment of Large Bowel Obstruction

The management of large bowel obstruction requires prompt diagnosis with CT scan with IV contrast as the gold standard, followed by either conservative management for partial obstructions without signs of peritonitis or ischemia, or surgical intervention for complete obstructions, signs of peritonitis, suspected bowel ischemia, or when conservative treatment fails after 72 hours. 1

Diagnostic Approach

1. Imaging Studies:

   • CT scan with IV contrast is the gold standard for confirming diagnosis, identifying location and cause of obstruction, detecting signs of bowel compromise, and evaluating for alternative diagnoses 1
   • Water-soluble rectal contrast can be administered when diagnosis remains uncertain 1
   • MRI is a valid alternative for pregnant women and children (sensitivity 95%, specificity 100%) 1

2. Laboratory Tests:

   • Complete blood count, lactate, electrolytes, CRP, and BUN/creatinine to assess the patient's condition 1

Management Algorithm

Conservative Management

Appropriate for:

• Partial obstructions without signs of peritonitis or ischemia
• Diverticular obstruction
• Sigmoid volvulus (often resolves with conservative treatment) 1

Conservative approach includes:

• Fasting
• Fluid and electrolyte replacement
• Bowel decompression via nasogastric tube
• Administration of water-soluble contrast agent 1

Surgical Intervention

Indicated for:

• Signs of peritonitis
• Suspected bowel ischemia or strangulation
• Failed conservative treatment after 72 hours
• Recurrent or non-reducible cases 1

Surgical options include:

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% in one study
   • Risk for conversion to open laparotomy (60% conversion rate) 1

Malignant Large Bowel Obstruction

Colorectal cancer accounts for over 60% of all large bowel obstructions 2

Management options:

1. Self-expanding metal stents (SEMS):

   • Option for malignant obstruction of the colon
   • Should be considered after multidisciplinary review 1

2. Surgical resection:

   • May be required for definitive treatment
   • Approach depends on patient condition and tumor location 1, 2

Special Considerations

Location-Specific Management

• Sigmoid volvulus: Often responds to conservative treatment 1
• Descending colonic volvulus: Extremely rare, typically requires surgical intervention 3

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: May have prolonged recovery; quality of life aspects particularly important 1

Medical Management Adjuncts

• Octreotide: 150-300 mcg SC twice daily to reduce secretions 1
• Corticosteroids: Dexamethasone up to 60 mg/day to reduce inflammation 1
• Prokinetic agents: May be helpful in partial obstructions but use with caution in renal impairment 1

Timing of Intervention

Prompt intervention (within 2 days of admission) results in:

• Decreased length of hospital stay (by approximately 3 days)
• Greater likelihood of discharge to home (71% vs 68%)
• No significant difference in inpatient mortality 4

Post-Treatment Care

• Early mobilization
• Progressive diet advancement when appropriate
• Close monitoring for signs of recurrent obstruction
• Begin oral nutrition if contrast reaches large bowel on follow-up X-ray after 24 hours 1

Common Pitfalls to Avoid

• Delaying surgical consultation
• Prolonging conservative management in patients with signs of strangulation
• 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