Bowel Obstruction Diagnosis and Management

Clinical Presentation

The American College of Surgeons recommends that patients presenting with lower right quadrant pain, leukocytosis, severe abdominal pain, nausea, vomiting, and abdominal distension be evaluated for bowel obstruction, with cardinal signs including colicky abdominal pain, absence of flatus (90% of cases), absence of bowel movements (80.6%), nausea/vomiting, abdominal distension (65.3%), and altered bowel sounds (hyperactive early, then absent) 1
Patients with bowel obstruction often exhibit abdominal distension, which is present in 65.3% of cases, and represents a strong predictive sign with a positive likelihood ratio of 16.8 1
The presence of fever, tachypnea, tachycardia, and confusion may indicate bowel ischemia or strangulation, which carries mortality rates up to 25% if not promptly treated and mandates immediate surgical intervention 1, 2

The American College of Radiology recommends CT abdomen/pelvis with IV contrast as the diagnostic standard for bowel obstruction, with >90% accuracy, and the ability to identify signs of ischemia (abnormal bowel wall enhancement, mesenteric edema, pneumatosis) that mandate immediate surgery 1, 2
Abdominal ultrasound can be used as an alternative with 90% sensitivity and 96% specificity, while plain abdominal X-rays have limited diagnostic value (sensitivity 50-60%) 1

Leukocytosis and neutrophilia suggest complications, while elevated lactic acid levels indicate possible ischemia, and low serum bicarbonate levels and arterial blood pH suggest metabolic acidosis 1

Consider appendicitis, stump appendicitis, right colon diverticulitis, right colon cancer, and bowel ischemia in the differential diagnosis of right lower quadrant pain with symptoms of bowel obstruction 1, 4, 5
CT abdomen and pelvis with IV contrast is usually appropriate for initial imaging in patients with RLQ pain, fever, and leukocytosis to evaluate for both appendicitis and bowel obstruction 4, 6