An 88-year-old female with dementia who recently had CABG develops marked abdominal distension, no bowel sounds, abdominal pain, and no bowel movements for 48 hours following surgery. A plain abdominal radiograph shows massive colonic distension with gas in the rectum. What is the most likely diagnosis?

• A. Ogilvie's syndrome
• B. Paralytic ileus
• C. Small bowel obstruction
• D. Mesenteric ischemia

Answer: (A)

Massive dilation of the colon after major surgery in an elderly patient points to acute colonic pseudo-obstruction, also known as Ogilvie’s syndrome. This condition arises from autonomic imbalance that slows colonic motility without a physical blockage. The colon becomes markedly distended, particularly the cecum and right colon, which can occur after surgery or in severely ill or debilitated patients. The key imaging clue is dilated colon with gas present in the rectum, indicating that there is no complete mechanical obstruction blocking the passage of gas and stool—distension is due to impaired motility rather than a true blockage.

This helps distinguish Ogilvie’s from a paralytic ileus that involves both small and large bowel with diffuse gas and often more generalized reduction in bowel sounds; it also differs from small bowel obstruction, where you would expect dilated small-bowel loops with relatively little gas in the colon and usually more prominent symptoms related to the early obstruction. Mesenteric ischemia would typically present with acute, severe pain out of proportion to examination findings and systemic signs, rather than isolated colonic dilation with preserved rectal gas.

In this scenario, the postoperative, elderly patient with marked colonic distension and gas in the rectum best fits Ogilvie’s syndrome. Management focuses on supportive care and monitoring for signs of perforation, with interventions such as pharmacologic decompression (neostigmine) or endoscopic decompression if conservative measures fail.