Ogilvie syndrome vs Paralytic Ileus

Colonic pseudo-obstruction (Ogilvie syndrome)

Colonic pseudo-obstruction, also known as Ogilvie syndrome, presents with signs and symptoms of colonic obstruction despite the absence of any mechanical cause of obstruction. Patients will show no signs of fecal impaction or strictures, other common causes of obstructions.

The exact pathophysiology isn't fully understood, but it's believed to involve a disruption of the enteric nervous system's ability to regulate colonic motility. This disruption is possibly related to an imbalance between excitatory and inhibitory signals that normally control intestinal movement. Common causes include recent surgery (particularly in hospitalized patients), use of opiates, trauma, or systemic illness. The colon is primarily affected in this condition.

Paralytic Ileus

This condition results from impaired neuromuscular function of the bowel. The underlying cause can be varied, including electrolyte imbalances, medications (particularly opioids), postoperative states, sepsis, or ischemia. Essentially, the bowel's ability to contract and move contents becomes compromised. It's a functional problem rather than a structural one; the bowel itself isn't physically damaged.

Because the entire bowel is affected in paralytic ileus, air-fluid levels may be seen throughout both the small and large intestine on imaging. While small amounts of air-fluid levels are normal, larger amounts indicate obstruction due to content buildup and impaired motility.