Acute Colonic Pseudoobstruction (Acute Megacolon, Ogilvie Syndrome) Clinical Presentation

Updated: Jan 24, 2020
  • Author: Roberto M Gamarra, MD; Chief Editor: BS Anand, MD  more...
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The typical patient acute colonic pseudoobstruction (ACPO) (acute megacolon, Ogilvie syndrome) is an elderly person who is in the hospital, usually for an unrelated reason (eg, postoperative recovery), and may or may not already be taking oral feedings. Procedures that commonly predispose to ACPO include spinal and orthopedic surgery (1-2%), cardiovascular or lung surgery (up to 5%), cesarian delivery, and burn injuries (0.3%). [12, 13]

Acute megacolon can occur on the medical wards as frequently as on the surgical wards (eg, in patients with unrelated problems, such as pneumonia, sepsis, myocardial infarction, or stroke). Systemic diseases that affect the neuromuscular component of the GI tract, such as amyloidosis, may first present with an acute episode of pseudoobstruction.

The most common presenting symptom is abdominal distention (89%), but not having a past history of similar episodes of abdominal distention is common. Other common presenting symptoms include abdominal pain (60-80%), nausea and vomiting (13-60%), constipation (50%), and, paradoxically, secretory diarrhea (20-40%), as well as fever in patient with complications (ie, perforation). [14, 15, 16]


Physical Examination

Physical examination findings in patients with acute colonic pseudoobstruction (acute megacolon, Ogilvie syndrome) may include the following:

  • The vital signs can all be normal.
  • Depending on the duration of the megacolon and the patient's fluid status, the patient may become tachycardic.
  • With distention of the abdomen pushing on the lungs, the patient also may develop tachypnea. In this regard, the lung fields may be decreased.
  • The abdomen is usually distended and tympanitic to percussion, with varying bowel sounds from absent to high-pitched. Serial measurement of the abdominal girth is routinely unreliable.
  • Digital rectal examination should generally be performed to exclude fecal impaction.
  • The presence of fever, severe tenderness, and peritoneal signs should raise the suspicion of colonic perforation or ischemia.