Difference between Ileus vs Small bowel obstruction

Paralytic Ileus

Postoperative ileus is transient impairment of bowel motility occurring after major surgery, generally due to a lack of coordinated bowel activity

Causes of Paralytic Ileus

  • The most common cause is abdominal surgery, including laparoscopic surgery. There is risk associated with cardiothoracic, gynecologic, genitourinary, and arthroscopic surgery
  • Electrolyte abnormalities (hyponatremia, hypokalemia, hypomagnesemia, hypermagnesemia)
  • Drugs (Opiates, anticholinergics, tricyclic antidepressants, calcium channel blockers)
  • Spine procedures
  • Uremia, mesenteric ischemia, myocardial infarction
  • Infections (peritonitis, intra-abdominal abscess, pneumonia)
  • Surgical factors correlated with a heightened chance of postoperative ileus
    • Duration of surgery
    • Amount of Blood Loss
    • The dose of opiate use
    • Tissue trauma in the gastrointestinal tract

Ileus vs Small Bowel obstruction

Ileus vs small bowl obstuction
Difference between Ileus and Small bowel obstruction

Diagnosis of Paralytic Ileus

Abdominal x-ray showing both small and large bowel loops dilatation till rectum is diagnostic of paralytic ileus. It can’t be always feasible to distinguish ileus from mechanical small bowel obstruction on frontal views. A lateral radiograph may help in this condition by showing air in rectum; however, ultrasound or contrast study may be required in equivocal cases. This is very helpful to distinguish ileus vs small bowel obstruction.

Management of Paralytic Ileus

Once ileus has occurred:

  • A nasogastric tube may decompress the stomach and relieve symptoms, and prevent aspiration in patients with nausea or vomiting
  • Administer IV fluids of isotonic dextrose-saline crystalloid or Ringer’s solution for postoperative maintenance
  • Wean opiate pain management and substitute sequentially with regular acetaminophen (paracetamol), regular NSAIDs (unless contraindicated), and regular or as-required tramadol and reserve opiates for breakthrough pain
  • Consider neostigmine IV infusion in some cases
  • Reserve surgery or invasive treatment for severe cases not responding to conservative therapies

Read more about the difference between types of cardiomyopathy and Mallory Weiss tear vs Boerhaave syndrome.


  1. https://pubmed.ncbi.nlm.nih.gov/2403907
  2. http://pubmed.ncbi.nlm.nih.gov/23114494?dopt=Abstract

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