Assessment and Management of Bowel Obstruction

Initial Clinical Assessment

The World Journal of Emergency Surgery recommends beginning immediate resuscitation with IV crystalloid fluids while simultaneously obtaining a focused history and performing targeted physical examination to identify high-risk features requiring urgent surgical intervention 1, 2, 3
Prior abdominal surgery has 85% sensitivity and 78% specificity for adhesive small bowel obstruction, according to the World Journal of Emergency Surgery 1, 2
Previous diverticulitis or chronic constipation suggests volvulus or diverticular stenosis, as stated in the World Journal of Emergency Surgery 1, 2
Rectal bleeding and weight loss indicate possible malignancy, as reported in the World Journal of Emergency Surgery 1, 2
Medications affecting peristalsis should be considered to differentiate from pseudo-obstruction, according to the World Journal of Emergency Surgery 1, 2

The Praxis Medical Insights guideline recommends that CT scan with IV contrast is the preferred diagnostic test with >90% accuracy for bowel obstruction and should be obtained immediately in all patients 3, 4
CT has ~90% accuracy for predicting strangulation and need for surgery, as stated in the Praxis Medical Insights guideline 4
CT identifies the level, cause, presence of ischemia, and multiple obstruction sites, according to the Praxis Medical Insights guideline 3, 4
Ultrasound has 90% sensitivity and 96% specificity when dilated loops >2.5 cm are visualized, as reported in the Praxis Medical Insights guideline 4
MRI is preferred for pregnant women and children (95% sensitivity, 100% specificity), according to the Praxis Medical Insights guideline 4

The Praxis Medical Insights guideline recommends that all patients require immediate nasogastric tube decompression, Foley catheter placement, and aggressive fluid resuscitation while determining operative versus non-operative candidacy 3
Marked leukocytosis with elevated absolute neutrophil count strongly suggests ischemia or perforation requiring urgent surgical consultation, as stated in the Praxis Medical Insights guideline 3

Immediate surgical intervention is mandatory for any patient with signs of ischemia, strangulation, or perforation (peritonitis, fever, hypotension, marked leukocytosis with elevated ANC), as recommended by the Praxis Medical Insights guideline 3
Clinical peritonitis or signs of strangulation require immediate surgery, according to the Praxis Medical Insights guideline 3
CT findings suggesting bowel compromise require immediate surgery, as stated in the Praxis Medical Insights guideline 3
Marked leukocytosis with elevated ANC requires urgent surgical consultation, as reported in the Praxis Medical Insights guideline 3

Adhesions are the cause of 55-75% of small bowel obstructions, according to the World Journal of Emergency Surgery 1, 2
Hernias are the cause of 15-25% of small bowel obstructions, as stated in the World Journal of Emergency Surgery 1, 2
Malignancies are the cause of 5-10% of small bowel obstructions, as reported in the World Journal of Emergency Surgery 1, 2
Cancer is the cause of 60% of large bowel obstructions, according to the World Journal of Emergency Surgery 1, 2
Volvulus is the cause of 15-20% of large bowel obstructions, as stated in the World Journal of Emergency Surgery 1, 2
Diverticular disease is the cause of 10% of large bowel obstructions, as reported in the World Journal of Emergency Surgery 1, 2

For malignant obstruction with signs of ischemia, the Praxis Medical Insights guideline recommends immediate surgical consultation and intervention; for those without ischemia, consider pharmacologic management and palliative procedures 3
Resection with primary anastomosis, intestinal bypass, or stoma creation may be considered depending on disease extent and patient status, as stated in the Praxis Medical Insights guideline 3
Opioids may be used for pain control, according to the Praxis Medical Insights guideline 3
Antiemetics (avoid prokinetic agents like metoclopramide in complete obstruction) may be used, as reported in the Praxis Medical Insights guideline 3
Corticosteroids may be used to reduce inflammation, according to the Praxis Medical Insights guideline 3
Somatostatin analogs may be used to reduce GI secretions, as stated in the Praxis Medical Insights guideline 3
Anticholinergics may be used to reduce secretions and motility, as reported in the Praxis Medical Insights guideline 3

Never delay surgical consultation when peritonitis, fever, hypotension, or marked leukocytosis are present, as recommended by the Praxis Medical Insights guideline 3
Never use prokinetic antiemetics (metoclopramide) in complete obstruction, according to the Praxis Medical Insights guideline 3
Never proceed to surgery without correcting electrolyte abnormalities and adequate resuscitation, as stated in the Praxis Medical Insights guideline 3
Never rely on plain radiographs alone to exclude bowel obstruction (only 50-60% sensitive), as reported in the Praxis Medical Insights guideline 4
Never administer water-soluble contrast before adequate nasogastric decompression, according to the Praxis Medical Insights guideline 4