Small Bowel Obstruction (SBO)

General Surgery

Overview

Definition

A mechanical blockage of the small intestines preventing the normal transit of its contents.

Epidemiology

A very common surgical admission. The most common cause in developed countries is post-operative adhesions.

Etiology & Risk Factors

  • Adhesions (from previous abdominal surgeries - #1 cause)
  • Hernias (incarcerated)
  • Neoplasms (Tumors)
  • Intussusception or Volvulus

Clinical Symptoms

  • Colicky (cramping) abdominal pain
  • Nausea and bilious (green) vomiting
  • Abdominal distension
  • Obstipation (absolute inability to pass stool or flatus) - a late sign

Clinical Approach

Diagnosis

  • Abdominal X-ray (Initial): Dilated loops of small bowel with air-fluid levels, and a paucity of air in the colon
  • CT Abdomen/Pelvis with IV contrast (Gold Standard): Can identify the exact transition point, cause of obstruction, and signs of ischemia (e.g., pneumatosis intestinalis)

Management

  • Initial (Conservative): NPO (nothing by mouth), IV fluid resuscitation, Nasogastric (NG) tube decompression
  • Surgical (Exploratory Laparotomy): Indicated if there are signs of strangulation/ischemia (fever, tachycardia, severe continuous pain, leukocytosis) or failure to resolve with conservative management after 3-5 days

Complications

  • Bowel ischemia and necrosis
  • Perforation leading to peritonitis and sepsis
  • Severe hypovolemia and electrolyte derangements