Timeline Criteria for Diagnosing Paralytic Ileus
Paralytic ileus is diagnosed when postoperative bowel dysfunction persists for more than 3 days after surgery, distinguishing it from normal postoperative ileus which resolves spontaneously within 2-3 days. 1, 2
Temporal Definitions
Normal Postoperative Ileus
- Expected duration: 2-3 days after surgery 1, 2
- Represents physiological inhibition of colonic motility that occurs after any operation 2
- Resolves spontaneously without intervention 2
Paralytic Ileus (Prolonged Postoperative Ileus)
- Diagnostic threshold: Bowel dysfunction lasting >3 days after surgery 1, 2
- Represents more severe inhibition, primarily affecting small bowel activity 2
- Requires active management and investigation 1
Clinical Context and Severity
The duration varies by surgical type and extent:
- Colonic surgery: Most extensive and prolonged ileus, with duration correlating directly with degree of surgical trauma 1
- Spinal surgery and lower extremity joint reconstruction: Higher risk in orthopedic patients 3
- Extraperitoneal surgery: Can develop even after non-abdominal procedures 1
Key Diagnostic Features Beyond Timeline
While the 3-day threshold is the primary temporal criterion, diagnosis requires:
- Clinical manifestations: Accumulation of secretions and gas causing nausea, vomiting, abdominal distension, and pain 1
- Absence of mechanical obstruction: Must exclude structural causes 4
- Impaired motor activity: Decreased or absent bowel sounds and peristalsis 4
Important Caveats
The 3-day cutoff is a clinical guideline, not an absolute rule. 1, 2 Some patients may require earlier intervention if:
- Severe symptoms develop before 3 days 4
- Risk factors suggest prolonged course (spinal cord injury, extensive bowel manipulation) 3, 5
- Signs of complications emerge (bowel perforation risk) 3
Radiologic evaluation should complement clinical assessment, with imaging showing dilated bowel loops with decreased peristalsis on ultrasound or CT when diagnosis is uncertain 6, 7