Contents
Occlusion or paralysis of the bowel preventing the forward passage of the intestinal contents, causing their accumulation proximal to the site of the blockage.
Classification
Mechanical ileus:
Mechanical obstruction of the gastrointestinal tract.
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External compression (adhesions, hernia)
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Changes in the bowel wall (tumour, inflammation/infection)
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Blockage of the lumen (coprostasis, intussusception).
Postoperative ileus (POI):
Temporary cessation of coordinated bowel peristalsis after surgery, restricting the passage of bowel contents and rendering the patient unable to tolerate the oral intake of liquids or solid food.
Paralytic/functional ileus:
Failure of normal intestinal motility in the absence of mechanical obstruction.
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Reflectory ileus—after abdominal or retroperitoneal surgery (e.g., spinal surgery), or induced by intra-abdominal or retroperitoneal lesions (tumor, hemorrhage, infection)
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Drug-induced ileus—due to the consumption of opioids, neuroleptic drugs, etc.
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Metabolic ileus—in patients with hypokalemia or diabetes mellitus
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Vascular ileus—due to hypoperfusion of the bowel.
Aetiology
- Adhesive disease (60%)
- Neoplasm (20%)
- Herniation (10%)
- Inflammatory bowel disease (IBD) (5%)
- Intussusception (< 5%)
- Volvulus (< 5%)
- Other (< 5 %)
Pathophysiology
Clinical features
Small-bowel ileus:
Presents acutely with severe symptoms.
- Persistent and copious vomiting
- Modest abdominal pain
- Minimal abdominal distention
Large-bowel ileus:
Presents with mild symptoms (volvulus of sudden onset is an exception).
- Significant abdominal distention and pain
- Malodorous vomiting (uncommon)
Complications
- Spontaneous perforation (3%)
Diagnosis
Plain radiograph:
Abdominal CT (GOLD STANDARD):

Exploratory laparotomy:

Differential diagnosis
- Ascites: Acute liver failure, history of hepatitis or alcoholism
- Medications (e.g., tricyclic antidepressants, narcotics)
- Mesenteric ischemia: History of peripheral vascular disease, hypercoagulable state, or postprandial abdominal angina; recent use of vasopressors
- Perforated viscus/intra-abdominal sepsis: Fever, leukocytosis, acute abdomen, free air on imaging
- Postoperative paralytic ileus (POI): Recent abdominal surgery with no postoperative flatus or bowel movement
- Pseudo-obstruction (Ogilvie syndrome): Acutely dilated large intestine, history of intestinal dysmotility, diabetes mellitus, scleroderma
Management
Conservative management (80%):
- Nasogastric feeding:
- IV fluid resuscitation (isotonic fluid)
- Aggressive replacement of electrolytes
- Antibiotics (treat intestinal overgrowth of bacteria and translocation across the bowel)
Surgical management:
- Indications:
- Strangulation, ischemia, complete absence of transit of bowel contents
- Acute abdomen
- Failure of medical management

Postoperative ileus (POI) prophylaxis:
- Minimally invasive surgery
- Thoracic epidural catheter
- Postoperative gum-chewing