What is the recommended management of a large bowel obstruction?

Management of Large Bowel Obstruction

Resection with primary anastomosis is the preferred surgical approach for most large bowel obstructions in hemodynamically stable patients without perforation, while immediate emergency surgery is mandatory when signs of peritonitis, ischemia, or perforation are present. 1, 2

Initial Resuscitation and Diagnostic Workup

Begin with aggressive supportive measures including intravenous crystalloid fluid resuscitation, nasogastric tube decompression for symptom relief, and Foley catheter insertion to monitor urine output. 2, 3 Broad-spectrum antibiotics should be initiated if perforation or ischemia is suspected. 3

Multidetector CT scan with intravenous contrast is mandatory to determine the cause, location, and presence of complications—it outperforms ultrasound and plain radiography for both sensitivity and specificity. 2, 3 Key imaging findings that mandate immediate surgery include pneumatosis intestinalis, free intraperitoneal air, closed-loop obstruction, and bowel wall thickening with poor enhancement. 3

Monitor continuously for clinical deterioration: diffuse peritoneal signs (guarding, rebound, absent bowel sounds), fever, tachycardia, confusion, rising lactate, and leukocytosis all indicate bowel ischemia or perforation requiring emergency intervention. 2, 3

Cause-Specific Surgical Management

Sigmoid Volvulus

• Without ischemia/perforation: Endoscopic detorsion followed by same-admission sigmoid colectomy with primary anastomosis is the optimal strategy. 1, 2
• Endoscopic detorsion alone should be reserved exclusively for high-surgical-risk patients, though recurrence rates remain high with this approach. 2
• With ischemia or failed detorsion: Immediate surgical intervention is required. 1, 2
• Laparoscopic surgery has limited utility due to the absence of sigmoid fixation and excessive colonic length making exposure difficult. 1, 2

Cecal Volvulus

• Endoscopy has no role—right hemicolectomy is the only option. 1, 2

Diverticular Obstruction

• Resection with primary anastomosis is the desired procedure regardless of bowel preparation status after successful conservative treatment in the same admission. 1, 2
• Conservative therapy alone or Hartmann procedure should be reserved for high-risk patients. 1, 2

Malignant Obstruction

For left-sided colonic cancer: Self-expanding metallic stents as a bridge to elective surgery offer superior short-term outcomes compared to emergency surgery, converting urgent cases to elective procedures with decreased complications and stoma formation. 2 Stenting is increasingly favored though long-term oncologic data continues to evolve. 3

For resectable disease in stable patients: Resection with primary anastomosis is recommended when significant risk factors or perforation are absent. 1, 2 Anastomotic leak rates in emergency settings range from 2.2-12%, comparable to the 2-8% rate after elective procedures. 1, 2

For high-risk patients or those with perforation: Staged procedures such as Hartmann procedure are necessary. 1, 2 Overall mortality for large bowel obstruction ranges from 11-22% depending on whether primary anastomosis versus staged procedures are performed. 3

For extraperitoneal rectal cancer: Postpone primary tumor resection and create a diverting stoma to permit proper staging and appropriate neoadjuvant treatment. 1, 2

Laparoscopic approach for malignant large bowel obstruction should be limited to selected cases in specialized centers. 1, 2

Special Populations: Palliative Care Patients

For patients with limited life expectancy (weeks to months) and malignant obstruction from carcinomatosis or unresectable tumor, medical management may be more appropriate than surgery. 1 Assessment of treatment goals (decreasing nausea/vomiting, allowing oral intake, pain control, facilitating discharge to home/hospice) should guide intervention choice. 1

Pharmacologic management includes:

• Octreotide 150-300 mcg subcutaneously twice daily or via continuous infusion—consider early due to high efficacy and tolerability in reducing gastrointestinal secretions. 1
• Opioids for pain control via rectal, transdermal, subcutaneous, or intravenous routes. 1
• Antiemetics (avoid prokinetic agents like metoclopramide in complete obstruction, though they may benefit incomplete obstruction). 1
• Anticholinergics (scopolamine, hyoscyamine, glycopyrrolate) to reduce secretions. 1
• Corticosteroids up to 60 mg/day dexamethasone (discontinue if no improvement in 3-5 days). 1
• Intravenous or subcutaneous fluids only if evidence of dehydration exists. 1

Endoscopic management options:

• Percutaneous endoscopic gastrostomy tube for drainage. 1
• Endoscopic stent placement when feasible. 1

Nasogastric tube drainage is uncomfortable, increases aspiration risk, and should be considered only on a limited trial basis if other measures fail to reduce vomiting. 1 Total parenteral nutrition should be considered only if expected improvement in quality of life with life expectancy of many months to years. 1

Critical Pitfalls to Avoid

Do not delay surgery beyond 48 hours when surgical intervention is indicated—mortality increases significantly with delayed intervention. 3 The "golden rule" mandates performing operations within 2 hours after diagnosis is determined in true emergencies. 4

Failed conservative management, clinical deterioration with rising lactate and white blood cell count, or development of peritoneal signs all necessitate immediate surgical exploration. 2, 3

Do not attempt laparoscopic adhesiolysis without careful patient selection—the risk of intestinal injuries is higher in laparoscopic surgery for bowel obstruction. 1